I I
H..3M...r$ufi
sake..- rm .

‘1” A.

  

   

 

 

{all

I§.__.‘3uwuan.

AMmul. Hmnzuuww.‘uw n W

   

3E

      

 

Y . lit... 2
.1 in“; TIL... I
«0' 1:30.41": .. 112.
2.0.4; A
45.:

.43.”.-

.J...S:An.1 J.

  

   

     
    
 

11M. on“. . . , . Wis! 1-!” .u‘...,.bx Llicl‘v
I . , :2 l .. . x .3... .z. .fill $1.4»; hflrul§1lfi i. ~23.
.‘ «Atalanbra...‘..:l.,..v......n......u...,4., mdwflkfldmrulumfimu ”Iva". "3.131." 41... .. A»... ah. In..- u.
1 n. ‘ ‘ . film" .. . ‘ \hfllflflftflv‘oflmkmfi‘mhuluu. c$vnvunwfllrm47
'

 

 

...
.l
i.

 

  

 

                                 

 

 

.4M4 . 1‘9.“ k

 

.. 3a .1 in! .'

. . at] u (.
J......w...#:

. D.

, n .

    

to
4.:
12.31%... 1.

'cfihflnnu. 5.13.... .n..llfl..flr..flb.u.4. ..

in“. W. Tm

       

          

                   

 

       

2) EJUVHH
I, (.1

    

    

dull.»
’

.r ”em. .

.rwaamfifiwp? .
.J . Eu m. hm. :. a

‘ J.wm20amxmwa.umh .wfil .wwfiw...

u. ..An....w%_.m.r.mw.fi.,..wm§w .r
u a .: .33..er refit».

      

  

    

       

 

‘fl

   

     

 

r
11. ..+ w .. IPSHVHHT»
I n 5.1.3le 115).!!. II. Ow}. :
«1L4. ; . u.

  
             

      

 

gt”. . .. u}?
1....Fvs.

£32.}
1.

          

  

 

JWMMWI 5:.

it.)
a

. . .rl
kflrtkmvtrwhw...
xv a 1.4:. sfi

J}?

       

 

   

{Icélohfiurl‘l .18 . xi;
,1: I l- .9 19...... . (a! 4 ..L1

(0500.“

 

 

. .Wwfimmr
..

     

   

  

v1,1|-’Up."..n.luhwbttll§.[.u.
. . . cal l
.rf- Ovlukrb:
t .I :v

 

 

 

 

. 1.010040 1.
‘ . .A 75.1 ‘K: Iliutylu} 31k!) )1.
. « Lt}...‘qltnl.|!3tunl.-’l.2|¢hvi¥

n I"<Anv

IAJC. I II It." Iv

      

 

 

,vl -. .1 ‘5 (LII-
, 3.1.311: . Quiz .3 pmmuw.v!.rttiil[ly

. {I .1. r!l.~ )le .C...ol‘ .vIAl .l..ln| . I. Ill. I

.,.r|l| 4. . I! O

W .. ‘ul‘llulluhl‘yTCHHdJ:nlu

E

    

      

     

   

                 

  

apt. . firikwmwmrfififl

  

        

           

«.SNU'V Jfiq: I - ‘
.thhnu, .LWowrn mam...» m

 

Irv: . J n. fil‘l’l‘il
. I 32.1.2“?! \tcclct? 0. l

J! .W cw... “unavudvan‘thh. “HILL.“ mh‘ k Illl

f

THESiS .

2

if /:‘ f

‘«
//'

Date

0-7 639

ICHIGAN STATE UNIVER

Ii mg; In:mIm:niiiiiniiil

3 1 93 01559 2508

LIBRARY

Michigan State
University

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This is to certify that the

thesis entitled

A

'n LABORATORY BASED STRA'“ECY FOR TEACHING
MICROBIOLCGY TO AT’RISK SECONDARY STUDENTS

presented by

Joseph G. Dailey

has been accepted towards fulfillment
of the requirements for

M.S. degree in 310801.

Division Of Science Education
Coldege Of Natural Science

%Mv €444M

Major professor

7/ 57/26

MS U is an Affirmative Action/Equal Opportunity Institution

 

PLACE ll RETURN BOX to remove We checkout from your record.
TO AVOID FINES return on or More dete due.

   

DATE DUE DATE DUE DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MSU le An W ActiorVEquel Opportunity lnetituion

m1

 

A LABORATORY BASED STRATEGY FOR TEACHING MICROBIOLOGY
TO AT-RISK SECONDARY STUDENTS

By

Joseph G. Dailey

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Division of Science Education
College of Natural Science

1996

ABSTRACT

A LABORATORY BASED STRATEGY FOR TEACHING MICROBIOLOGY
TO AT-RISK SECONDARY STUDENTS

By

Joseph G. Dailey

The thesis documents the revision of the class, Tales From The Petri
DE, so that students will obtain a basic knowledge of what bacteria and fungi
are and how this knowledge and microbiological techniques are used in the
worlds of business and research. The primary means to accomplish this goal
is the development of several meaningful laboratories and learning
experiences including units on food microbiology and plant pathology.

The subjects in the study are students at an alternative high school
which is a drop-out prevention program for at-risk students at the secondary
level. The data collected includes pre—tests and post-tests, clinical interviews,
descriptive demographic information and student evaluations of laboratory
exercises.

Despite generally weak academic records prior to the class, all students
achieved scores one to three times higher on the post-test as compared with
the pre-test. Also, students in the clinical interviews reported positive

attitudinal changes.

To Terri, for everything.

iii

ACKNOWLEDGEMENTS

The process of researching and writing this has taken place over a few
years. In that time it has been my pleasure to interact with a number of
persons regarding the work. Cheryl Hach has been a great supporter and
sounding board, full of helpful information, late-night lab partner and a
friend. Merle Heidemann as the leading professor and liason with the
program at M.S.U. has been extremely professional, competent and patient.
Professor Ray Hammerschmidt's assistance has been invaluable, he has given
me a great deal of his time and many good ideas. The students in all three
sections of the class during the research period were uniquely themselves but
they empathized with me in the role of student and took the class seriously.
The classes offered by the Division of Science Education including the
Summer Workshops and Frontiers Workshops were extremely valuable so I
am grateful to all those persons who taught them, whether I used something
from their class or not. Finally I would like to thank my friends and family,

especially Terri DeForrest for their support.

iv

TABLE OF CONTENTS

 

 

 

 

INTRODUCTION .................................................................................................. 1

CHAPTER 1

SUMMARY OF SCIENTIFIC CONCEPTS BEHIND

UNITS OF THE CLASS ........................................................................................ 13

CHAPTER 2

IMPLEMENTATION OF THE COURSE ........................................................... 20
Outline of Units ......................................................................................... 24
List of Field Trips and Labs ...................................................................... 27
Audio-visual Aids ..................................................................................... 29

CHAPTER 3

SUMMARIES OF LABS AND FIELD TRIPS .................................................... 32
Field Trips .................................................................................................... 33
Labs ................................................................................................................ 38

CHAPTER 4

EVALUATION OF THE COURSE ..................................................................... 54
I. Pre-test and Post—test Statistics ............................................................. 54
II. Demographic Information About Students in
Tales From The Petri [M ...................................................................... 56
HI. Analysis of Pre-Class and Post-Class Student Interviews ........... 60

CHAPTER 5

CONCLUSIONS ..................................................................................................... 78
What Was Effective in TALES FROM THE PETRI DISH? ............... 78
What Needed Improvement in TALES FROM
THE PETRI DISH. ...................................................................................... 82

BIBLIOGRAPHY .................................................................................................... 87

APPENDICES

Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
Appendix 1
Appendix I
Appendix K
Appendix L
Appendix M
Appendix N
Appendix O
Appendix P
Appendix Q
Appendix R
Appendix S

Appendix T

Microbiology Is....& Sterile Technique .......................... 90
Enzyme Notes .................................................................... 92
Bacteria Notes ..................................................................... 93
Fungus Notes ..................................................................... 95
Food Microbiology Notes ................................................ 96
Plant Pathology Notes ...................................................... 97
Plant Pathology Slides ...................................................... 100
American Chestnuts and Chestnut Blight ................... 102
Tissue Culture Notes ........................................................ 104
Tales From The Petri Dish Final Exam-

Winter Semester '96' ........................................................ 105
Student Pre-Class Interview 8: Student
Post-Classlnterview ........................................................... 112
Field Trip To Winery Report Form ............................... 116
Tissue Culture Experiment ............................................. 117
Brewing Beer ...................................................................... 119
Chestnut Blight ................................................................. 122
Acquired Systemic Resistance In Cucumbers .............. 124

PD3, 4 and 5 Student Pre-Test &

Post-Test Results ................................................................ 126
PD3, 4 and 5 Student Demographic Data -
Age and GradePoint .......................................................... 128
PD3, 4 and 5 Student Demographic Data -
Attendance .......................................................................... 130
PD3, 4 and 5 Student Demographic Data -
Grade Level ......................................................................... 132

Vi

INTRODUCTION

This document reports the revision of a class entitled Tales From The
Petri Dish (PD). I taught two versions of the class, PD1 and PD2, prior to
beginning my study. The first class was an attempt to put into practice some
of the exciting lab exercises I did at Michigan State University's 1990 Cellular
and Molecular Biology Workshop and the Frontiers of Physical and Biological
Science Workshops held throughout the academic year. In the second
offering, I organized the class around a central question after learning of this
approach from Dr. Glenn Berkheimer at the Environmental and Behavioral
Biology Workshop, also offered by M.S.U..

I teach at an alternative high school in southwestern Michigan. For
reasons of confidentiality, it shall be referred to by a portion of it's acronym
(AHS). The school opened in 1986 as a dropout prevention program of the
sponsoring school district from which generally provides 60% of our student
population. We accept students from six other districts in the county with
whom we have reciprocating agreements. All of our students are at-risk for
not completing high school and are referred to us for any number of reasons
including but not limited to pregnancy, poor attendance, disruptive behavior,
court referral or self-referral. Generally, AHS students are below grade level

in most or all skills; some are well below. Class sizes are relatively small,

with 15 or fewer students. This is essential given the large amount of
assistance and support that at-risk students require. Most of the student body
is in the typical high school age range of 14 to 18 years of age. We also have a
small but consistent percentage of adult students who are generally between
19 and 30 years of age. These adult students attend the same classes as the
alternative students including 'I_"_a_les From The Petri Dish.

Another teacher (at one-third time) and I comprise the AHS science
department, as a result course offerings are limited. We offer as basic courses,
one year of biology and one year of physical science, generally taken by
freshman and sophomores. Upper level classes one-semester long are Str_ea_m
333m and Tales From The Petri Dish. Miscellaneous short courses with such
names as Environmental Clean-up. Project Wild and Proficiencvfi Test
Preparation are also offered as needed.

AHS students select classes in consultation with the school counselor.
I supply the counselor with a list of students that I think would be suited to
the PD class; some of those students elect to take the class. The counselor
generally follows my selections in fact, and always in spirit. There are
scheduling constraints imposed by having a population of only 100 students
and 7 to 8 instructors teaching a class during any one class period. Generally
there will be a few students in each section that either have had the class
before or were not on my list (because they are new students or PD is still the
best available fit). I base my list on personal observations in and out of class

using various subjective judgements such as maturity, intelligence,

perseverance, attitude and attendance. The students in the PD classes are
some of the best at AHS. However, if these same students were at a
traditional high school, it is my opinion, that they would for the most part
rank in the lower half of their class.

Though difficult to quantify, students display many disruptive and self-
defeating behaviors. One of those is poor class attendance. We have an 80%
attendance policy: if a student is present less than 80% of the marking period
(not including excused absences) they will not receive credit. In any given
marking period (20-25 school days) anywhere between 5 and 20% of students
lose credit. PD3 started with 12 students though only 5 attended enough
classes to receive credit. The next section started with 12 students and 11
received credit. Our students are also fairly transient. Of the approximately
100 students who begin the year about half will be replaced by someone else by
the end of the year.

Generally AHS is not a violent place. We have only a handful of
actual fights each year and no-one has ever been apprehended with a gun,
though pocket knives are fairly common. What is common is low self-
esteem and it's results - apathy, disengagement and acting out.

In the 1995-96 school year, AHS serviced 168 students with
approximately 100 of them being enrolled at any one time. Of these 168
students, 63 were referred to Time-Out (TO). These numbers do not include
out-of-school suspensions. T0 is a separate room and has two uses: in-house

suspension and a place to send students when the instructor sees fit to

remove them from the classroom. In most cases a student is in T0 for
between 10 and 55 minutes, or one to three days in the case of an in-school
suspension. TO is a boring place and most students truly prefer being back in
the classroom. We have found negative aspects but it does allow one to carry
on a classroom lesson without disruption. Additionally, students are not able
to sit and enjoy the action in the office. Below is a breakdown of students by

frequency of T0 referrals.

Number of students with 15 or more TO referrals - 17
Number of students with 5 or more TO referrals - 23
Number of students with less than 5 TO referrals - 23

Number of students who had no TO referrals - 105

I use textbooks infrequently in my alternative high school classes. It is
the informal policy of all AHS teachers to not assign homework.
Consequently any reading for content takes place during class time and I
prefer to use that time with students in more active pursuits.

PD was first offered in Winter Semester, 1993. The class had time
available for relatively involved experiments because it met two and one-half
block class periods per week over 18 weeks (a block class period is 110 minutes
long). It's premise was to allow students to try a number of lab exercises on a
wide variety of biological topics. Basically, my goals then and now are the

same: help students to more meaningfully learn science, they should enjoy

the experience and they should be motivated to go further in science either
through study or work. I believed that simply increasing the amount of
"hands-on" learning I offered to students would accomplish these goals and
to some extent that was true. Students did enjoy the opportunity to do more
experiments. However, I do not think students learned a lot or were so
engaged by the class that they would choose to pursue more science. I
recognized that my students might perform better in a structured
environment within which they are given responsibility. In contrast to that
thought, PD1 was more of a biology experiment sampler without a strongly
unifying theme. Also, Tales from the Petri Dish did not generate the same
student excitement as my upper level environmental science class called
Stream Team.

I attended the Environmental and Behavioral Science Workshop
offered by M.S.U. at the Kellogg Biological Station in the summer of 1993.
The culminating project of that summer was to produce a unit plan based on
the formulation of a central question as explained by Dr. Glenn Berkheimer
of M.S.U. I chose Stream Team to revise for my unit plan. In using the unit
with students in the fall Stream Team class, I feel there was great
improvement in student understanding though I have no data to
substantiate this belief. Heartened by this academic improvement, I wanted
to bring aspects of a "central question" to the PD2 class and chose as my theme
"Microbiological Technology-How People Use Fungi and Bacteria." Some

topics from PD1 and 2 are discussed later. I saw the results of these changes as

positive in terms of student achievement and reducing student frustration.
Choosing to revise the Petri Dish class as my thesis project is simply
continuing this trend.

I chose to continue teaching microbiology at AHS and therefore to use
it as the area of my thesis work, for a number of reasons. I have had some
upper level course work in that area. I have a personal interest in the subject
and briefly considered pursuing a masters degree in plant pathology. From
the students' point of view, microbiology has value in that it has a great
impact on our lives, which will only increase as technology advances, in areas
such as food production, health safety and medicine. For many AHS
students, career possibilities literally do not go far beyond auto-mechanics and
truck-driving. I think this is at least partly because of their backgrounds.

They have few role models in other professions and many of their parents are
unemployed. Given these facts, at-risk students are particularly in need of
familiarity with and information about a broader range of career choices. I

hope that PD will provide some of that for them.

Effective techniques for the instruction of at-risk students is not a topic
that receives a large amount of attention in the science education literature.
However, two common and inter-related themes emerge from what is
available. One is that the course should be designed in a way that connects
content with the real world. The second is that at-risk students have special

needs in the area of engagement and self-esteem that must be addressed

before they can be effective learners. I believe these relate back to the three
goals I mentioned earlier in the introduction. The need for varied
pedagogical approaches to educate a_ll students is also supported by the science
education literature.

All students who receive science instruction do not learn equally well.
Several studies have documented a wide range of outcomes. LaPointe (29)
found that 14-year old science students in the US ranked 14th (of the 20
counties) in a survey of science and math achievement. The bottom 10
percentile of students had fewer than 35% correct responses. Clearly they
have not learned science in a meaningful way.

Tobias (37) believes that successful programs for at-risk students should
involve students with use of concrete materials in applying science
principles. Hill and Hounshell (28) saw dramatic improvements in the test
scores of high school students in a remedial summer biology class. The
course was designed so that there was an emphasis on process skills and real
world applications of information. Vatter (38) says that schoolwork for at-risk
students should be "hands-on" and tied to real work in the real world.

Regarding the special needs of at-risk students, the context that has
produced them must be considered (1,2). While these students have
undeniable skill deficits, they too often possess the necessary intelligence but
are simply not personally involved with their studies. For some reason they
have learned to discount the value of schooling. Steele (36) discusses the

experience of many African-Americans who have failed to thrive

academically. For African-Americans who have done well academically in
one educational setting, the change to a different setting where they
experience stigma has frequently led to academic decline. The stigma that
Steele refers to is a lack of belief in an individual students' abilities based on
their group rather than what the individual student has demonstrated. I am
sure that this phenomenon of stigma is not restricted only to African-
Americans and that other groups experience it on the basis of their class or
another characteristic. Experience of this stigma is part of the context that
produces at-risk students.

Newmann (32) refers to the opposite of this alienated behavior as
engagement. Some of the characteristics of instruction that lead to
engagement are that students feel membership in their school, that they are
doing authentic work with a connection to the real world and that it has an
element of fun. Yager (39), in discussing ST S (Science, Technology and
Society, a curricular focus promoted by the National Science Teachers
Association), emphasizes that education should include a strong component
of career awareness especially relating to science and technology.

In summary, my thesis problem is to revise Tales From The Petri Dish
in such a way that students will obtain a basic understanding of bacteria and
fungi and how this knowledge and microbiological techniques are used in the
real world of business and research. The primary means to accomplish this
goal are the development of several meaningful laboratories and learning

experiences.

As mentioned previously PD 1 and 2 preceded my actual study but
some valuable activities were developed. I shall briefly describe those that in
a more highly developed form have been part of PD during the period of my
study. The general pattern for lab experiences was to first discuss background
information as a class. Then students would perform and report on the
experiment. The report format is based on the Scientific Method as typically
presented in most high school science textbooks. As a way to learn the
reporting format students were asked to develop a question on any topic that
seemed reasonable and practical. One example was "How consistently made
are seemingly identical objects?" To answer this, the student individually
weighed each one of a large number of paper clips on an electronic balance.
Another student studied fly feeding preferences.

Students planned a one-day program of sampling for coliform bacteria
at 20 sites on two local river systems using Redigel premixed selective medias.
The intent was to develop a picture of where and to what extent fecal
contamination existed on the PawPaw and Black River systems.

The first version of the experiment Bacteria Are Everywhere was in
PD1. Students cultured soil and epiphytic bacteria on nutrient agar in order to
observe the variety of the colony morphologies and "prove" that bacteria are
present even though invisible to the naked eye. The students initially did not
show a great deal of interest in what we had grown. Interest increased when I
directed their observations by pointing out what I could see. In the course of

discussion the statement was made "It's pretty hard to get excited about

10

something when you don't know what you're looking at". It had not
occurred to me beforehand that students would want to identify the different
types of bacteria we found so I wasn't prepared to help them do that. From
this experience I saw two needs (which were addressed in the classes taught
during the research period) - a better way to steer the students into closely
observing colonies and something that would meet their need to know what
they were looking at.

Using a tissue culture kit from Kemtec, we cultured carrot seedlings. I
wanted to include tissue culture in the course because it relies on sterile
technique and other microbiology skills and is a practical application of these
skills. Seeds were placed on a germination media and remained there until
seedlings had formed. Students transferred seedling stem sections to callus
forming media and later transferred callus to cloning media. The resulting
seedlings could then be potted. Contamination was present at every stage and
resulted in only two seedlings being healthy enough to plant.

Obviously sterile technique was used in some of the activities from
PD1 but in PD2 I presented it as a discrete topic. Students practiced sterile
technique skills on their own and studied the newly developed handout
entitled Microbiology Is... & Sterile Technique (appendix A). I found that later
projects went more smoothly when students could concentrate on an
experiment without the pressure of having to simultaneously learn sterile
technique.

In the second version of the experiment Bacteria Are Everywhere we

11

grew bacteria from three sources - the air (dishes left open in various places
for various lengths of time), infusions of distilled water and soil, field grass
and beans, and the human body (coughing onto a plate and touching a plate
with unwashed fingers). The bacteria which happened to grow were used in
the next two experiments.

To direct students toward closer observation of colony morphologies
than had occurred in PD1, I gave them a list of colony features. For a given
colony they would make comments about each of these features. Each
student would be responsible for reporting on several different colonies. This
system did improve student observations and the time they were willing to
spend on it. However, students did not have a broad enough vocabulary to
express the differences that they saw. For example, a colony may have an
internal filamentous appearance that can be one of six different patterns (i.e.,
arborescent). My students, in looking at that might say something like "it had
a lot of hairs." When I would press them to be more specific they were
generally unable to respond and experienced a high level of frustration.

In another improvement over PD1 regarding bacterial observation,
students took samples of the cultures grown in class and made fixed slides
using solutions from a Frey kit. We learned together as I had only done this
once before in a college microbiology class. Due to poor technique, most
slides were not viewable but students enjoyed the process of fixing and
staining.

Using a Kemtec kit, "Enzymes in Industry", the class compared the

12

rates of juice production from applesauce treated with pectinase and
untreated sauce. This experiment was relatively simple to perform but it did
not capture student interest. I think this is because at-risk students are not
aware of the importance of enzymes. Additionally, I had not provided
enough information to correct this nor had I explained the importance of
enzymes in other experiments we were doing in the class.

In keeping with the purpose of PD2 as stated in the syllabus, I took the
class to the medical technology lab of a local hospital. Students viewed the
equipment and techniques used in a modern facility and, where applicable,
compared them with what we used in the classroom. I believe this allowed
them to see an application for the skills and information they had been

learning.

CHAPTER 1

SUMMARY OF SCIENCE CONCEPTS BEHIND EACH UNIT OF PETRI DISH

Microbiology is a very broad field of study and as a result it can be
defined in different ways, depending on the perspective of the person
providing the definition. My students might define it as "the study of

organisms that are only visible under the microscope." I would have them
add to this "and all of the impacts of the relationship between microbes and
other organisms, especially humans." While my students might think that
the role of microbiology is to look at such things as the physiology and
reproduction of bacteria and fungi, my message for them is larger. For as long
as humans have existed they have had a relationship to microbes. Microbes
are responsible for diseases that have evolved along with us, not to mention
their role in decomposition and the cycling of atmospheric gases.
Humankind began in prehistoric times to harness some microbes in the
production of foods and beverages. In the last few hundred years, through
methodical scientific analysis, humans have begun to understand and
manage microbes in the area of medicine, the environment, wastewater

treatment, industrial production, plant pathology and others. In the

13

14

following section I have included the majority of the information I selected

for my students to learn.

I. Sterile Technique (ST)

ST (34) is the most important basic concept for a laboratory based
microbiology class for several reasons. There are many bacterial and fungal
spores in our environment and that can have positive or negative results. It
is good, for example, that decomposers are mobile enough during some
portions of their life cycles to colonize new food sites and keep nutrients
cycling through the environment. It is usually bad for the quality of foods in
the home that these same decomposers are so mobile. As the concept of ST
pertains to classroom activities, I stress that it allows us to study only the
organisms of interest without contamination. The use of sterilizing liquids,
such as alcohol and bleach, and different forms of heat for sterilization are
discussed and practiced (autoclaving, flaming, boiling and baking). A petri
dish is of most use when it is properly managed. In general, the student
should be aware of the need to keep containers sterile and reducing exposure

to contaminants when they are studying microbes.

II. Enzymes
Enzymes are proteins that serve as catalysts for chemical reactions.
Originally discovered in yeast, it is now recognized that enzymes are found in

all forms of life Because they are part of all life functions, enzymes are

15

essential for the existence of all organisms. Each enzyme performs a specific
task and that specificity is a result of the unique shape possessed by each type
of enzyme. Factors that affect the rate at which an enzyme functions include
temperature, pH, presence of inhibitors and the concentrations of reactants.

Extreme temperatures can denature an enzyme.

HI. Bacteria

Bacteria are single celled prokaryotes and were probably the first form
of life on the planet (33, 16). Some are photosynthetic but most absorb
nutrient molecules through the cell wall and membrane. Bacteria most often
reproduce asexually by simple cell division though they do have some
characteristics, such as mutations, that introduce variation. The average
doubling time is twenty minutes. At this rate one microscopic bacteria can
produce a colony visible to the naked eye within twenty-four hours. Bacteria
live in the widest variety of environments of any organisms on earth
including aerobic and anaerobic conditions. Bacteria can be identified and
classified in a number of different ways. The individual cells have one of
three basic shapes - spheres, spirals and rods. Groups of bacteria ranging in
number from a few to several thousand or more exhibit one of three
grouping patterns - chains, sheets and clusters. Gram stains can be used to
identify bacteria because the presence or absence of peptidoglycans in the cell
walls of different types determines which of two stains are retained. Bacterial

types vary upwards from zero in the amount of the enzyme catalase they

16

produce. Types of bacteria also vary in their level of resistance to commercial
antibiotics. At the level of a whole colony, each bacterial type has visually
observable, consistent physical characteristics when grown on solid media in
a petri dish. Example of these characteristics include thing such as the
colony's profile shape, the way the colony's edge is shaped, light transmission
and so on. All of these characteristics can be used in the classification and

identification of bacteria.

IV. Fungi

Fungi are an extremely varied group of organisms. In general they are
multicellular eukaryotes where the cells are arranged in long strings called
hyphae. Hyphae are not themselves reproductive structures; rather they are
the phase of the fungal life cycle concerned with growth and acquiring
nutrition. A mass of hyphae is called a mycelium. When the average person
thinks of fungi they are usually picturing a reproductive structure like a
mushroom or green bread mold. Of the total fungal biomass in the world
most is in the form of these hyphae. Most fungi obtain food by externally
digesting a food source and then absorbing the resulting molecules through
the cell membrane. In addition to digestive chemicals, fungi are also capable
of producing an incredible variety of compounds generally for the purpose of
defense, an example being the antibiotic penicillin. Fungal cell walls are
usually made of the polysaccharide chitin, a material also found in the

exoskeletons of arthropods. Spores are produced by sexual and asexual means

17

and are thick walled in order to survive hostile conditions. Sexual

reproduction occurs in most fungi, though the form of it varies widely.

V. Food Microbiology

The fermenting microbes are important in the production of many
foods. Anaerobes obtain the energy to support cellular activities from their
food sources through fermentation. Over the history of humankind we have
selected microbes that produce desired compounds as by-products of normal
fermentation. One example is the production of alcohol for beverages usually
accomplished by one of a large variety of yeasts. Cheeses, butter, yogurt and
sauerkraut are a result of lactic acid fermenting anaerobes. Carbonation, the
"fizz" in beverages, is a result of the production of carbon dioxide by various

microbes as is the rising of leavened bread.

VI. Plant Pathology

Two groups of organisms, fungi and bacteria, are responsible for the
majority of diseases known to afflict plants (24). Of these, the fungi are
responsible for most of the known diseases. In a typical successful fungal
infection of a plant, a spore will land at an opportune exterior location. From
there it will grow a series of structures designed to adhere to and enter the
body of the plant. Hyphae or other structures will either enter inter-cellular
spaces or the cells themselves and begin digesting and/ or absorbing food.

There are two major possible causes of an unsuccessful infection . One, the

18

environmental conditions are not appropriate for the pathogen; many fungi
require humid conditions for spore germination. Two, the plant is not
susceptible to that particular pathogen. There are several thousands of
identified plant diseases but only 10 to 20 of them are able to infect any one
species. Plant defenses are of two types, passive and active. The passive
category includes solid barriers like the hard surface of a potato or chemicals
that are always present such as the phenols that give pines their distinctive
odor. Active defenses include the production and delivery on demand of
special chemicals such as chitinase which breaks down fungal cell walls.
Also, rapid local cell death (hypersensitive response) controlled by a host
plant can prevent the spread of the fungus at the cost of only a few cells rather
than the death of the entire plant. Plants and their pathogens are constantly
evolving their defenses and offenses such that commercially developed
resistances in food crops generally last no more than five to ten years. Since
it's accidental importation in 1907, Chestnut Blight has decimated the
American Chestnut (4,8,). The fungi responsible for the blight, Endothia

parasitica, may be cultured in the lab.

VII. Tissue Culture

Tissue culture (5, 17,18) is the production of an entire organism
originating from a small piece of that organism by the use of hormones,
techniques borrowed from microbiology and specific culture conditions .

Tissue culture is theoretically possible with complex animals though to date

19

only some animal cells and organs have been cultured. Meanwhile,
perennial plants such as the hosta have been produced in commercially
valuable quantities. In this process, plant hormones (such as kinetin and
indole acetic acid) stimulate the formation of de-differentiated or callus tissue
from a small piece of the original plant. Then large numbers of whole plants
in seedling form sprout from the edges of the callus tissue. These may be
removed, planted and grown in the same manner as any seedling. The
growers at Walters Gardens have found that plant vigor increased in the first
generation after culturing. Tissue culture differs from simple vegetative
propagation in the need for sterile conditions, the formation of callus tissue

and the larger numbers of plants produced from a single piece of plant.

CHAPTER 2

IMPLEMENTATION OF THE COURSE

I taught Tales From The Petri Dish three times during my research
period: PD3 was Fall Semester 1994, PD4 was Winter Semester 1995, PD5 was
Winter Semester 1996. A complete list of experiments and learning
experiences is found later in this chapter. Briefly, the revised PD classes differ
from PD1 & 2 in several ways. Some topics were dropped for various reasons
and others added. The section presenting basic information about bacteria
was restructured. A section about fungi was added. The study of the
relationship between plant pathogenic microbes and plants, which included
experiments to investigate Chestnut Blight and induced resistance in
cucumber, was added. The selection of food microbiology laboratories
changed - making cottage cheese was out, making sauerkraut, ginger ale,
yogurt and brewing beer was in. Basic information about enzymes and
additional experiments to demonstrate this information were added.
Learning sterile technique was basically the same.

PD5 differs from it's two immediate predecessors in that I have

dropped the topic of tissue culture. Because microbes are not involved in the

20

21

tissue culture process it is technically not microbiology, though it does use
techniques derived from microbiology. My experience with tissue culture
over the first four classes tells me that the problem of contamination makes
the effort not feasible under conditions in my classroom. Students were
enthusiastic at the start of the project, but the high frustration due to
contamination and the fact that each step takes so long caused them to lose
interest.

Some new teaching techniques were required to reach the goals
mentioned in the introduction. In choosing which experiments to include I
considered these goals by asking key questions. Would the experiment help
students to more meaningfully learn the scientific concepts laid out in the
previous chapter, Summary Of Science Concepts? Would my students be
excited by and enjoy doing the experiment in terms of feeling and being
successful? Would students doing this experiment possibly be motivated to
explore the subject further? Other important factors were matters of
practicality such as time constraints and availability of the necessary
equipment.

The other reason for including these new teaching techniques is to
make sure the students have an experience that reinforces each of the
concepts in the post-test (see appendix I). To that end there is a field trip for
each of the main topics of the course. I also wanted to fill out the work on
bacteria and enzymes and provide work in the new areas of plant pathology,

fungi and food microbiology.

22

Not all new teaching techniques were a new experiment or field trip.
Discussed below are some changes in teaching style. As stated earlier, I opted
to create a more highly structured environment than had existed in PD1 and
2. An experiment, preparation for an experiment or a field trip was scheduled
for each day of the unit before the first day of class. By contrast, in PD1 and 2,
I had left a great many choices about direction of the class up to the students.
Students were responsible for making all the media used in class during the
research period. In preparing for labs, I would often ask the students to design
the procedures to be followed in order to achieve sterile conditions.
Sometimes students did not finish time-sensitive experiments promptly or
were careless so that their results were flawed. I could have easily taken
responsibility and fixed the problem, but I think that my students need to see
the consequences of their actions. This meant the students in these situations
needed to repeat the entire lab. They were good humored about this and
generally did not repeat the same mistake.

Since I was not using a textbook, there had to be one place where
students could find explanations and summaries of the concepts they needed
to know. I wrote and typed all the notes students would need (see appendices
A through H) to meet this need. Each of the items on the post-test was
included in the notes. I chose to use pre-written notes because I have found
previously that the process of students taking notes while I lecture uses more
time than should be necessary. Also, since my at-risk students just copy what

I write on the overhead (in many cases words are mis-spelled and the

23

penmanship is unreadable even by the student) does the exercise in any way
lead students to mentally process the information. Most importantly, the
information is not retained for long by many of the students. Each time that I
distribute pre—written notes, I make the bargain with my students that I will
continue to present notes this way as long as they are willing to read aloud
and maturely discuss them. The discussions have often been quite good and
the pre—written notes are certainly no worse than the lecture/ notetaking
model.

I used a wide variety of sources to obtain the information presented in
the PD classes. Most of the plant pathology information comes from personal
conversations with and presentations given by Dr. Ray Hammerschmidt
(25,26) and Dr. Dennis Fulbright (14,30). Both are professors at M.S.U. and
have suggested experiments they thought suitable for high school students at
their presentations. I had other useful conversations with Professor Tom
Corner (9) and graduate student Michelle Anderson (3), also at M.S.U. All of
the kits purchased from Kemtec (5,27) have arrived with well-written and in-
depth manuals that allow me to adequately discuss the results with students
while having more information to add if required. Another source was the
lab write-ups distributed to participants of the 1990 Cellular and Molecular
Biology Workshop and class lecture notes from the same. At a 1992 Frontiers
of Biological Science session Fred Ham (19,20,21,22,23), a public high school
science teacher, presented several labs which I have borrowed and adapted to

my needs. Other books, journal articles and miscellaneous items I have used

24

can be found in the bibliography.

I. OUTLINE OF BASIC UNITS

PD3 8t PD4 contained six basic units and PD5 contained five since tissue
culture was dropped. A brief discussion of each is found below arranged
chronologically with the approximate time allotted to each topic. A block
class period is 110 minutes in length and one school week consists of five
block periods. PD3 was taught between October 31, 1994 and January 20,1995.
PD4 was taught between January 23, 1995 and March 20, 1995. PD5 was taught
between January 22, 1996 and May 16, 1996. Since PD5 was taught over a
longer period of time the reader should proportionately increase the amount

of time shown below that was allotted to teach each unit.

Introduction 1.5 weeks

At the start of the unit, a pre—test was administered to determine the
beginning level of student knowledge of microbiology. Additionally in PD5,
clinical student interviews (see appendix K) were conducted at the beginning
and end of the class to determine student attitudes regarding microbiology
and their knowledge of the subject. Analysis of that information may be
found in chapter 4. The majority of time, however, was spent providing
students with information about enzymes and basic skills necessary to
perform later labs.

All aspects of sterile technique needed for successful completion of

25

later lab experiences are introduced at this point. The skills were refined and
practiced in the lab experiences.

Understanding the nature and functions of enzymes is important to an
understanding of microbiology since they are one of the primary ways that
microbes act on their environment (i.e., how microbes obtain nutrients). In
large part, food microbiology and plant pathology are examples of disciplines
that study the action of microbes in the environment. For almost all students
that have entered my classroom, enzyme is a meaningless word. If I want
them to understand what a microbe is doing, I must teach them what an

enzyme is.

Tissue Culture (PD 3 and 4) 0.5 weeks

I saw the tissue culture facility at Walters Gardens on a tour in 1981. I found
the concept very exciting. As stated earlier, I included tissue culture in the
course because it relies on sterile technique and other microbiology skills and
is a practical application of these skills. Technically, the culturing process was
started just after the pre—test since the entire process takes every bit of nine
weeks. Also, it is still an unusual technique to use in a high school classroom

and I wanted the students to experience something unique.

General Information about Bacteria 2 weeks
This unit contains critical information for appreciating these microbes and

understanding later topics, especially food microbiology. I did not treat this as

26

a distinct unit in PD1 8r 2 nor did I cover as much material. It became
apparent that students entering my classroom knew very little about bacteria
other than myths and misunderstandings. Therefore, in order to increase
understanding and reduce frustration, more classtime was spent on covering
basic information about bacteria. Also, since I already had most of the
required equipment, performing the appropriate experiments was very

feasible in my classroom.

General Information about Fungi 1 week
The same comments made for the General Information about Bacteria unit

can be made about this unit also.

Food Microbiology 2 weeks

This unit has been a prominent part of the class since PD2. Since everyone
eats food, microbiology fits into all students' prior knowledge. I assumed that
it would be the best applied topic for raising student interest. Additionally,
students would be able to eat and drink the products and use what they learn

at home immediately.

Plant Pathology 2 weeks

Fungi are the. primary disease agents of plants so this unit fits well into
microbiology. Plant pathology is a "hands-on" way to look at microbiology in

disease situations without the risk of infection that would come with

27

studying human pathogens. As with tissue culture, plant pathology offers an
opportunity for an experience that is unique in the high school classroom. In
addition, I have a personal interest in the topic and have often found that I do

my best teaching when that is the case.

Conclusion

A post-test, which is included in the appendix, was administered at or
near the end of the term scheduled for the PD classes. In PD5 clinical entrance
and exit interviews were conducted with the same group of four students. A
third evaluation tool administered in the PD5 class was a student evaluation

of the experiments and field trips in a self-report format.

11. LIST OF FIELD TRIPS AND LAB EXERCISES

Following is a listing of each lab exercise and field trip that students
experienced in PD 3 through 5. Summaries of each activity are found
following the list. Activities on the list marked with an asterisk are either
new since PD1 and 2 or significantly altered from the form they had in those
early classes. Some exercises did not occur in all three classes during the
research period. These exercises are labeled on the list with parentheses
enclosing the numbers of the classes in which they did occur. If no class

number is shown the exercise occurred in all three classes.

28

FIELD TRIPS

Walters Gardens" - Tissue Culture (PD3 & 4)

Campbell's Fresh" - General Information About Fungi

Hospital Medical Testing Lab - General Information About Bacteria
St. Julian Winery* - Food Microbiology

Collecting Chestnut Bark" - Plant Pathology

LAB EXERCISES
Tissue Culture (PD3 & 4)
Enzyme Characteristics
Degradation of Lactose"
Silver Retrieval from Photographic Film
Juice Extraction from Apple Sauce
Gelatin and the Effect of Boiling on Enzymes in Pineapple*
Sterile Technique
Making Culture Ready Petri Dishes including Potato Dextrose Agar *
Use of NiChrome Transfer Loops and Miscellaneous Skills
General Information about Bacteria
Bacteria R Everywhere"
Serial Dilution to Determine Food Contamination (simulation, PD4)
Using Selective Media to determine aquatic fecal contamination
Bacteria Identification -
Making Stained Permanent Slides
Colony Morphology*
Catalase Reaction" (PD4 & 5)
Isolating Pure Cultures (from the Bacteria R Everywhere plates)
Looking at Bacteria with Microscopes"
General Information About Fungi
Culturing Fungi in classroom" (PD4)
Fungus Garden" (PD3 & 5)
Spore Print (demonstration)"
Serial Dilution to find best concentration of molasses and yeast (PD5)
Food Microbiology
Brewing Beer"
Making Sauerkraut"
Making Ginger Ale"
Making Yogurt"
Plant Pathology
Culturing and Transferring Bark Carrying Chestnut Blight"
Assessing Virulence of Chestnut Blight Strains (PD3)*
Staining for Lignin" (PD4)
Acquired Systemic Resistance in Cucumbers"
Microbiology Meal" (PD4)

*

29

HI. AUDIO-VISUAL AIDS AND OTHER DEMONSTRATIONS
A. PD calender - Self-developed

At the start of each semester since beginning my research I distributed a
PD calendar to the students. The calender is in a Monday-through-Friday
format and creates for the student a "map" of the class. Listed are the
approximate dates for covering the five units of the class, when we will do
each experiment, important tasks, and, when applicable, times and
destinations of field trips. Also listed are dates of the pre-test and post-test,

and any early-release or no-school dates.

B. TC slides — from Kemtec Tissue Culture Kit

A set of six photographic slides comes with the Kemtec Tissue Culture
Kit. They show what the plant material should look like at each stage in the
tissue culture process. This is useful because students may look at the slides
to compare classroom results with the desired results rather than relying on
my knowledge. In this way they are required to take responsibility for making

judgements for such things as knowing when to transfer tissue to a new plate.

C. Fungus/ Plant Pathology Photographic Slides - from Dr. Hammerschmidt
This series of twenty-six slides is used as part of my introductions to

both the Fungi and Plant Pathology units. I emphasize different aspects of the

images in each of the introductions. Most of the slides show disease agents

and / or the symptoms they produce in their host plants. The images are

30

useful because they make the variety and effect of plant diseases more real
than any other method I have available in the classroom. Interest is generally
high. I believe this is because we have an active two-way discussion of what
is viewed. Also, perhaps, being at-risk and adolescents (for the most part)
they enjoy the images of "gross" things. The slides were obtained by copying
those that Dr. Ray Hammerschmidt uses in an introductory university
course. The notes which accompany presentation of the slides are in

appendix G.

D. American Chestnut Dried Specimens - Self-developed

Since the American Chestnut is rare, students are generally unfamiliar
with it and need to be educated about it's gross morphological characteristics.
I have collected chestnut branches and leaves, seed casings, dried flowers,
cankered bark and nuts from various locations to show to students. Looking
at these props is useful, especially when we go to collect cankered bark,
because the students have a better idea as to what they are looking for. Also,
given the lack of botany experiences in most K-12 systems, I believe there are

intangible benefits in students seeing all of these plant parts together.

E. "Cultural Characteristics of Bacteria" - from Dr. Tom Corner
I acquired this four page key to bacterial colony morphology from Prof.
Tom Corner of the M.S.U. Microbiology Department after PD2. It has several

diagrams to illustrate descriptive terms that students can use to classify a

31

colony according to it's profile, edge texture, transparency, overall shape and
internal texture. I ask my students to observe bacterial colonies on petri
dishes so that they can develop an appreciation for their variety and because
observation is indispensable tool of science. Students can readily access a
broad vocabulary by matching the live colony to the pictures and then simply
writing down the appropriate descriptor. Students in PD1 and PD2
attempting to describe the appearance of colonies without the key experienced
a great deal of frustration because my expectations were greater than their
verbal skills and vocabulary could meet. Also, importantly for at-risk
students, the hand-out provides structure since students know what they are

looking for, reducing fear of the unknown.

F. Prepared Microscope Slides - from Carolina Biological Supply Company
These prepared microscope slides show the three most common
bacterial shapes (bacilli, spirilli and sphere) and typical ways that bacterium
will group together (sheet, cluster and chain). After observing these closely,
students are able to identify the shapes and grouping patterns on fixed slides
that they prepare from live cultures more than half the time. Students also

look at prepared slides of fungi for such things as reproductive structures.

CHAPTER 3

SUMMARIES OF LABS AND FIELD TRIPS

Students evaluated most of the labs and field trips in a self-report
format at the end of PD4 and 5. The three numbers found below many of the
following summaries are results from the student evaluations. For each
experience listed on the evaluation students were asked to assign a range of
values from 1 to 5 as answers to three questions. Question one was "How
much did the experiment grab your interest?" Question two was "Do you
think you understood the experiment?" Question three was "How much did
the experiment help your understanding of the topics in the course?" The
scores were derived by finding the percentage of positive response to the
question. The more frequently that students answered a question positively,
the closer a score is to 1.0 The ratings can be interpreted much like a grading
scale; values of 0.90 and above are very good and a value between 0.60 and
0.70 indicates the experiment was acceptable but could use improvement.

I encouraged students to be honest, not to worry about my feelings and

that nothing they said would affect their grades. Students appeared to take

the opportunity seriously and gave a variety of values as answers in PD5. In

32

33

PD4 only six students completed the evaluation and usually four or five of
them gave the same high value to all the activities. It would seem to me that
students who write nearly all of one value simply want to be done with the
task quickly. In PD5 all 15 students completed the evaluation and the values
appear to be significantly less clustered. For these reasons I consider the
evaluations by PD5 students to be valid evaluative information and these are

the only values shown.

I. FIELD TRIPS

All field trips were taken during or near the end of the unit of which
they are a part. I chose these points, rather than using the trips as part of an
introduction, because my previous experience indicates that at-risk
adolescents need prior familiarity in order to understand and develop an
active interest in what they are seeing. For each field trip students were to
return a report form to me. The questions were similar on each form. A

sample, from the St. Julians Winery trip, is included in appendix L.

A. Walters Gardens Tour- PD4 only

We toured Walters Gardens as part of the tissue culture unit. Walters
Gardens is a producer and wholesaler of perennials specializing in hostas.
Walters begins the tour with a slide show describing the business as a whole
and the particular methods of tissue culture used at the facility.

Unfortunately, the bulk of the walking tour does not focus on tissue culture

but on the complex of warehouses, cold rooms, packing rooms, fields,
greenhouses, etc. Approximately ten minutes were spent in the tissue culture
rooms which is comprised of a media preparation room, an incubation room
and plant processing room, the last two being sealed and sterile. Students
were generally enthusiastic about tissue culture at the start of the unit but
between the experimental failures discussed later and the nature of the tour
that enthusiasm quickly declined. I feel this was because of the seemingly
extraneous walking through warehouses and the like and that students were

kept from getting close to the activity in the tissue culturing rooms.

B. Campbell's Fresh Tour

This is probably the best all—around of the trips for combining student
interest and seeing the application of microbiology. Students are able to touch
most everything and get up close to see. Our guide all three times was
friendly, humorous and full of information. This is a very large production
facility so it was possible to see all stages in mushoom culture. They are:
1) Composting of manure (to which water, gypsum and cottonseed meal are
added) for one month in a large open air shed.
2) After the micro-organisms in the compost have done their work the
majority of them must be killed. This is done in large rooms where the
compost is steamed at 65% moisture between 150 and 180°F for several days.
By this point the compost has been loaded into mobile 8' X 8' X 1' beds.

3) Mycelium of the desired species comes to the facility in bags that are kept

35

refrigerated. Campbell's has a lab in Kentucky where they grow the

mycelium under optimal conditions with an eye towards quality control.
Students can handle these bags and make the connection between those white
threads inside and specimens we have seen back in the classroom.

4) Mycelium and the prepared compost are mixed together and placed in the
spawn rooms where, over the next two weeks, the mycelia spread throughout
the beds.

5) To stimulate formation of mushrooms the environmental conditions are

altered by adding a layer of peat moss, raising the humidity, lowering the
temperature and increasing the level of C02.

6) Mushrooms are harvested by hand over 3 to 4 "breaks" or crops. The
mushrooms are then packaged and shipped. Of course the thing that widens
the student's eyes is that the mushrooms have not been washed prior to
being sent to stores. They both love and are repelled by that.

Interest-0.98 / Comprehension-.96] General Understanding-0.96

C. St. Julian Winery Tour

This is the most anticipated tour due to alcohol's allure for teenagers.
As a local tourist attraction, St. Julian offers tours every half hour followed by
a tasting session. Groups are run through the plant rather quickly and as a
result there is little time to pursue things of special interest to my students as
we encounter them. Students see several aspects of the operation: grape

processing (where they are crushed and screened); aging (where special oak

barrels and fermentation locks are of interest); viewing the high pressure
metal champagne vats and the bottling room. In PD5, I mentioned to the
guide that we were a microbiology class and she arranged for us to visit the St.
Julian lab. The purpose of the lab is quality control and they monitor such
things as alcohol content, color and suspended solids The value of this field
trip is uneven, the ability of the guide to answer questions seemed to vary
greatly and was affected by whether or not tourists accompany the group. But
there is fun to be had by students standing around the sampling bar and
ordering drinks, albeit non-alcoholic ones. See report form in appendix L.

Interest-0.95/ Comprehension-.87/ General Understanding-0.89

D. Collecting Chestnut Bark

After much searching and invaluable assistance from M.S.U.'s Dr.
Fulbright, I located a hill five miles from school with about a hundred
clumps of American Chestnuts. Considering the efficiency of Endothia
parasitica, the fungal blight that has ravaged these trees, this is quite a stroke
of luck. In addition, the owners have generously agreed to allow me to bring
classes there occasionally to see the trees and take some bark samples for
culturing in the classroom. Students may never again see this many
American Chestnuts and they can also clearly see the effect of the Blight on
the trees. Students look for the cankers caused by E. parasitica on the
dormant and leafless trees and cut out a small section of bark containing the

characteristic orange-red pustules. Students see how the clumps of American

37

Chestnuts sprout from the stumps of long dead larger trees and see for
themselves the woods' rot-resistance in the form of large standing snags. I
feel this is a valid opportunity for my students to see that microbiology can
include outdoor field work which appeals to some persons more than a career
spent predominantly indoors. The last stop is an isolated, live American
Chestnut that is approximately 150 feet tall and whose circumference can be
enclosed by 4 people holding hands with arms fully extended. This trees'
beauty and tenacious grasp on life despite being infected by the blight is
impressive.

Interest-0.85/ Comprehension-.89/ General Understanding-0.91

E. South Haven Hospital Medical Technology Lab (PD5)

As in PD2, I took the class to the medical technology lab of a local
hospital. Students viewed the equipment and techniques used in a modern
facility including a blood cell counter, blood chemistry analyzers and a
microbiology bay. I believe this allowed them to see an application for the
skills and information they had been learning. As the microbiologist was
explaining how she might identify various pathogens I overheard students
commenting on how similar many of the pieces of equipment were to those
at school and how the microbiologist's duties were similar to what we had
done in class.

Interest-0.83] Comprehension-.85/ General Understanding-0.83

II. LABS
A. Tissue Culture

There were two differences between methods of tissue culture
attempted by the PD3 and 4 classes (5,17,18). The techniques described in
appendix M were used in PD3 but not in PD4. One was the method for
germinating the seedlings. The second was the type and sequence of media
used in the rest of the tissue culturing process. If contamination had not
become a problem the Murashige & Skoog medias we used in PD3 (A, B, C
and Control) would have been useful for demonstrating the effect of varied
hormone concentration on callus formation.

In PD4 I tried a kit from Kemtec using radish seeds instead of the carrot
seeds provided in the kit. I had previously used this same kit and was able to
plant a few carrot seedlings produced by the tissue culture process. Due to
miscommunication between myself and the students, the callus forming
dishes were sealed with Parafilm instead just being left in a closed, sterile
plastic bag as recommended in the kit instructions. Probably as a result of
insufficient gas exchange the seedlings didn't form callus very readily. When
this mistake was discovered we removed the Parafilm and left the dishes in a
plastic bag as recommended. Contamination was again a major problem.
Since it was late in the marking period by the point that the problems were
recognized there would not have been sufficient time to complete the process

so the next step, transferring the stem sections to cloning media did not occur.

39

B. Enzyme Characteristics
The first two labs are taken from Fred Ham, a high school teacher, who
presented them at a Frontiers Workshop. The second two labs come from a

Kemtec kit entitled Enzymes in Industry.

1. Degradation of Lactose

Individual students have two containers of milk (21). One is untreated and
the second is treated by adding Lactaid, containing lactase which degrades
lactose into galactose and glucose. The containers are allowed to sit in a
refrigerator overnight. On day 2 students taste milk from the two containers
to see if they can discern a difference in sweetness. In addition, the students
dip urinalysis glucose strips into the two liquids and compare this with the
accompanying color chart. The color chart results correspond to values on
Masterson's relative sweetness scale. Lactaid drops or crushed pills work
equally well .

Interest-0.62] Comprehension-.84/ General Understanding-0.89

2. Gelatin and the Effect of Boiling on Enzymes in Pineapple

Gelatin is freshly prepared but before it is allowed to harden, four different
liquids are added: juice from canned pineapple, juice from fresh pineapple,
and solutions of the commercial tenderizers Adolph's and McCormick's (22).
The different gelatins are refrigerated overnight and observed the next day.

Typically the gelatin treated with canned pineapple juice is the only one that

40

will set up firmly. Students are asked to hypothesize about why that
happened. Obviously the pineapple's enzymes have been denatured by heat
in the canning process.

Interest-0.71] Comprehension-.84/ General Understanding-0.86

3. Silver Retrieval from Photographic Film

The students put small strips of unhardened, exposed photographic film in
test tubes and add an aqueous solution of protease (27). The film strips are a
"dispersion of silver halide in gelatin on a firm backing." The protease
enzyme has the ability to degrade the gelatin as it is a protein. Within 20
minutes the dark emulsion which contains gelatin has obviously started to
slough off some of the strips due to protease action. The literature that comes
with the Kemtec kit informs us that a portion of the dark precipitate is silver.

Interest—0.78/ Comprehension-.77/ General Understanding-0.78

4. Juice Extraction from Apple Sauce

The students set up two funnels and graduated cylinders each containing
filter paper and identical amounts of apple sauce (27 ). One batch of sauce has
been treated with the enzyme pectinase, the other is untreated. As pectinase
breaks up the pectin, water remaining in the plant tissues is released from the
treated apple sauce, which consistently produces a greater volume of juice.

Interest-0.72] Comprehension-.80/ General Understanding-0.88

41

C. Sterile Technique

1. Miscellaneous Skills

Except in one case, all media used in the class were made by the students (34).
Each section produced approximately 120 nutrient and potato-dextrose agar
plates. During the preparation of the first set of agar plates several other new
skills and methods were acquired by the students. These include sterilization
of work areas with a bleach solution, uses of Parafilm, inverting dishes with
and without inoculated media to avoid condensation landing on the surface
and flaming flask mouths. See appendix A for details.

Interest-0.69/ Comprehension-.76] General Understanding-0.79

2. Use of NiChrome Transfer Loops

Students practiced effective use of transfer loops, using plain water and empty
non-sterile plates. When I was satisfied that they had attained this skill
students were allowed to proceed to the next unit of the class including the
Bacteria R Everywhere experiment.

Interest-0.75] Comprehension-.87] General Understanding-0.87

D. General Information about Bacteria

1. Bacteria R Everywhere

As a whole class, students brainstorm possible locations where bacteria might
be living. We prioritize the list of locations to insure variety and then

students choose one or a few locations to investigate using previously learned

42

microbiological techniques. Students are required to write an experimental
proposal detailing their hypothesis or question, what will serve as the
experimental control, number of replicates, how experimental conditions are
controlled, data recording format and procedure. Once I am satisfied with
their proposal, students may perform their experiments and then report their
results. Reports are graded based on the students handling and interpretation
of the data.

Interest-0.84] Comprehension-.88/ General Understanding-0.88

2. Bacteria Identification

a. Making Stained Permanent Slides

After learning by study of commercial prepared slides the shapes of
individual bacteria and the three grouping patterns (chain, cluster and sheet),
students make there own slides (13). They find a culture of interest from
their Bacteria R Everywhere plates, fix them on a slide and then stain with
one of six stains (saffranin, crystal violet, etc). The students then must
microscopically determine the shape of a bacterium and it's grouping pattern.
Interest-0.90/ Comprehension-.91/ General Understanding-0.91

b. Colony Morphology

Using a diagram (9) that illustrates descriptive terms, students classify a
colony as to it's color, profile, edge texture, transparency overall shape and
internal texture. This works very well because it supplies structure in the

form of pictures and vocabulary words to match up with the appearance of

43

colonies. I overlooked colony morphology and the catalase reaction when
writing the form for the student evaluation of labs. However, based on their
comments I would estimate that students liked the latter more than the
former and that both would have had values in the range between making
stained permanent slides and isolating pure cultures.

c. Catalase Reaction

Bacterial species vary in the amount of the enzyme catalase that they contain
(3). This can be demonstrated by putting drops of hydrogen peroxide on part
of a colony. I had my aide find 3 or 4 of the most widely differing cultures and
we used those as a reference for a scale of reactivity. The students determined
the reactivity of their cultures and added this to information they compiled

regarding characteristics of bacterial cultures.

3. Isolating Pure Cultures

Again, using the Bacteria R Everywhere plates, students transferred and
streaked cultures of interest onto new plates in order to determine if those
cultures were pure. The students as a group were not highly engaged by
doing this. It did work well however to assign the majority to an un-
supervised task while I worked with two students in choosing and trans-
ferring the cultures. These students enjoyed the experience.

Interest-0.67/ Comprehension-.71/ General Understanding-0.75

4. Using Selective Media

Students obtain water samples from a creek using sterile technique to
determine the level of aquatic fecal contamination (31). The samples are then
used with EPA approved materials from RediGel in a two step process. In the
first, the petri dish media additive Violet Red Bile (VRB) encourages the
growth of coliform bacteria and discourages the growth of any other bacteria.
These colonies are counted and then results are expressed as number of
colonies per 100 ml. A number of these colonies are transferred using sterile
technique, to a second dish containing the additive Eosin Methylene Blue
(EMB) which shows by a color change if any of them are the non-pathogenic
E. coli bacteria usually associated with the feces of mammals. This media also
discourages the growth of other bacteria.

Interest-0.63/ Comprehension-0.70 / General Understanding-0.73

5. Serial Dilutions

The technique of the serial dilution is useful in determining the
concentration most appropriate to a particular situation. The PD4 students
applied this technique to determine food contamination in a simulation (6).
After a brief discussion of the math involved and food contamination
measurement methods, students made tenfold dilutions (1:1 to 1:10,000) of
colored water observing the decreasing color. They reported to me on the
value of such a technique in the food industry and procedures involved.

In PD5 serial dilutions were used to "determine the optimal

45

proportions of yeast solution and molasses-water mixture needed to produce
the greatest amount of carbon dioxide gas" (11). I gave some background
information but it was the student's responsibility to find a way to determine
the optimal proportion. Generally individual students tried only one or two
different proportions and the group realized the next day that because of this
they were not close to an answer. I explained how having a range of several
different proportions from very little yeast and lots of molasses to the other
extreme would cover all the possible proportions. The students were then
able to adequately determine the optimal combination of yeast, molasses and
water on their next attempt.

Interest-0.78] Comprehension-.78/ General Understanding-0.80

B. General Information About Fungi

1. Culture fungi in classroom

In PD3 and 5 we constructed a Fungus Garden (10). An aquarium was
prepared with a moistened 1" sand layer. Students placed objects (foods,
fabric, etc) in the aquarium and then sealed it. Over time a variety of fungi
grew and the Garden came to be "gross", in the students' words, which made
it attractive to adolescents. The students were enthusiastic about setting up
the Garden but remembering to make informal follow-up observations
required prompting.

In PD4 we attempted to culture fungi in petri dishes (12) but it was less

entertaining which is why I returned to the Fungus Garden for PD5.

Interest-0.87/ Comprehension—.90/ General Understanding-0.88

2. Spore print (demonstration)

Using large mushroom caps from Campbell's Fresh, the students and I made
spore prints. This is done by leaving a fresh, de-stemmed, mushroom cap
undisturbed on top of a piece of paper. We fixed them onto the paper

satisfactorily using hair spray.

F. Food Microbiology

The first two food microbiology projects below depend on fungi, the
second two on bacteria. Brewing is the most complex process; the other three
can basically be set up by students within 15 to 30 minutes. One problem is
that with the exception of beer, these foods are not normally eaten by my
students. As a result the enthusiasm was not as strong as I expected. I may

substitute other foods in future classes.

1. Brewing beer

When brewing in the usual manner, it is not desirable to open and close the
container each day due to the chance of contamination. I wanted students to
trace the changes in the yeast population (7) and amount of alcohol in the
beer on a daily (or nearly so) basis. In order to do this we mixed one master

batch, poured it into the bottles and allowed brewing to proceed in vitro (see

47

appendix N). We saw a large jump in the yeast population and alcohol
content during the first three days. Considering the conditions under which
we made it I was not interested in drinking any of the beverage, however, the
color, odor and head produced seemed very similar to commercial products.
Students, as anticipated, were very enthusiastic about this project and did not
fail to follow-up.

Interest-0.96/ Comprehension-.89/ General Understanding-0.89

2. Making Ginger Ale

Students mix grated fresh ginger root, sugar and other flavorings with yeast
so that the whole will ferment (20). After the mixture is allowed to sit at
room temperature for at least six hours, the solids are filtered out which stops
fermentation and yields a moderately carbonated beverage. A difficulty is in
the timing because the fermentation would not be completed until after the
end of the school day. I asked students remember to come back in order to
refrigerate the mixture overnight and get it out of the refrigerator at the start
of the school day so that fermentation is completed. The students have
remembered to complete these tasks about half the time.

Interest-0.87/ Comprehension-.85/ General Understanding-0.85

3. Making Sauerkraut
Students finely chop green cabbage, add 2.5% salt by weight and mix (23). The

mixture is put into a container and allowed to sit at room temperature for a

period of a few weeks. Lactobacilli naturally found on the cabbage proliferate
in this environment and through the production of proprionic acid (that
characteristic sauerkraut smell) transform the cabbage into kraut. Finding
some way to continually compress the kraut improves the process. The salt
pulls juice out from the cabbage so there is a liquid environment for the
bacteria. As the lactobacilli continue degrading the cabbage there is a decline
in volume of approximately 25%. One quart jar out of the 12 produced in
PD3, 4 and 5 was eaten. Our school librarian reports that it tasted acceptable.

Interest-0.68/ Comprehension-.85/ General Understanding-0.83

4. Making Yogurt

The process of making yogurt is quite simple (19). Microbes in the raw
material, skim milk, are killed by heating. After the milk mixture cools and
acidophilus bacteria are stirred in, it goes into sterile receiving containers
which are closed and incubated at room temperature. Yogurt should form in
one to two days. Students in PD4, at first hesitantly and then readily,
consumed their yogurt at the Microbiology Meal (discussed later). Students in
PD3 and 5 did not eat their yogurts because, I suspect, I did not set aside special
time for tasting it.

Interest-0.70 / Comprehension-.84/ General Understanding-0.84

49

G. Plant Pathology

This section is the most problematic, most original and my favorite. Drs.
Fulbright and Hammerschmidt had not written up these experiments for use
in the classroom or tested them with high school students. Consequently
they are still in early stages of development and adaptation to my classroom.
Also, proper scheduling of events in these lengthy procedures, (lengthy at

least by the standards of at-risk secondary students) has proven so far to be

difficult.

1. Culturing and Transferring Bark Carrying Chestnut Blight

After collecting samples of bark (see field trips) it is cut into dime or quarter
sized pieces. The exterior is "sterilized" by soaking in dilute bleach and then
the piece is pressed lightly onto a potato dextrose agar plate (see appendix 0).
Within 7 days those pieces that will produce a blight mycelium will have
done so. Blight fungi cultured in this way may be assessed to determine it's
virulence (see next section). One significant problem has been
contamination of the plates by an unidentified green fungus. Dr. Fulbright
suggested trying different bleach concentrations and soaking times. In PD5 we
had much better success when soaking the bark pieces in 30% and 40% bleach
solutions as compared with the 10% bleach solution Dr. Fulbright had
originally suggested.

Interest—0.85/ Comprehension-0.83] General Understanding-0.85

50

2. Assessing Virulence of Chestnut Blight Strains

It is possible to determine virulence by looking at a culture's growth form on
a petri dish but a more definitive test is available. Students remove a small
plug from a Golden Delicious apple using a hand cork borer (see appendix 0).
They use the same size bore to get a plug of the mycelia and place that in the
apple. Within 14 to 21 days an adequate portion of the apple will have rotted
to determine virulence. If the rotted area has the correct size and shape it is
virulent. If contamination has occurred the rotted area will be a color other
than medium-dark brown.

Because of contamination and scheduling problems, PD3 was the only
class to do this experiment so no values from the student evaluations are
listed. I would estimate the interest and enthusiasm of that group for this
experiment to be in the high moderate range. I was not entirely certain in
PD3 that the mycelia we chose to test for virulence was Chestnut Blight
because the results we obtained were inconclusive. Much of what is written
above comes from conversations with Dr. Fulbright subsequent to and
regarding the experience in PD3. Obviously this experiment needs
refinement but I believe further efforts are worth-while given it's score for
question 1 (interest, rank of fourth overall) given to the lead-in experiment,

Culturing and Transferring Bark Carrying Chestnut Blight.

51

3. Staining for Lignin

One defense mechanism that plants employ after being attacked by pathogens
is the creation of tough, lignin bearing walls. In order to see this students
remove the outside layer from cucumber seedlings and stain them for lignin
using 1% phloro-glucinol and HCl (25). Typically not much is seen at this
point. Then the seedlings are inoculated with spores of the pathogen,
Colletotrichum lagenarium. The inoculated plants are kept in damp, dark
location for two to three days before the students again peel and stain the
outside layer. This time some areas of lignin are plainly visible and on close
inspection even the fungal structures stimulating this phenomenon can be
seen. Students commented that they would have liked to spend more time

on this experiment.

4. Acquired Systemic Resistance In Cucumbers

Ray Hammerschmidt declared in his Frontier's presentation that plants have
something like an immune response. That seemed like a novel and
intriguing way to look at things. He also maintained that it would be possible
to demonstrate this in the classroom, which is the point of this experiment
(see appendix P). The premise is that if a cucumber is inoculated with a non-
killer pathogen then it will be stimulated to resist a second inoculation by a
killer pathogen. My classes were unable to actually complete the experiment.
In PD3, I had not allowed enough time for the cucumber seedlings to grow

given the low light conditions in December and January. In PD4 and 5, the

52

plants were ready. However, we were unable to produce viable cultures for
the inoculations. Although the experiment was not completed, students
experienced a reasonable approximation of the experiment because of three
things. They read and intelligently discussed the hand-out I developed. The
students raised the plants to the extent possible. They also saw a
photographic slide comparing the effect of Colletotrichum lagenarium on
two cucumber leaves. One leaf was from a resistant plant and the other leaf
was from a susceptible plant. It is clearly visible in the picture that the
resistant plant's leaf was inoculated in roughly the same pattern as the
susceptible plant's leaf except that the former exhibits none of the necrotic
lesions found on the latter. Additionally, 60% of the PD5 students correctly
answered the question about this test on the post-test. Given these facts I
conclude the experiment is within the abilities of at-risk students and will
continue to use and perfect this experiment in future PD classes.

Interest-0.81/ Comprehension-0.77/ General Understanding-0.77

H. Microbiology Meal - This idea came from the students and a how-to article
by Gillen and Williams (15). Students in PD4 expressed an interest in a party
at course end. I countered by suggesting a Microbiology Meal. The concept of
the Microbiology Meal is that all food and beverage items consumed, except
for condiments and flavorings, must have somehow been produced by
microbes . "Produced" can be widely interpreted if need be. The students

must be able to verbalize the microbial connection. On the day we planned

53

the menu the students as a group suggested the foods and gave their
microbial credentials. Our menu was this:
mushrooms (from our tour of Campbell's Fresh)
hamburger (serial dilution simulation of measuring food contamination)
yogurt (produced in class)
ginger ale (produced in class)
potatoes (-dextrose agar and the Black Scurf sclerotia on the skin)
cheese
milk (can be made into yogurt)

This activity only occurred in PD4 and I did not ask the students about
it on the lab evaluation form though I am certain they would have given it
high values. There was no Microbiology Meal in PD5 for reasons having

nothing to do with it's value as a learning reinforcement activity.

CHAPTER 4
EVALUATION OF THE COURSE

I. Pre-test and Post-test Statistics

The numerical results of the pre-tests and post-tests for each student in
PD 3, 4 and 5 are listed in appendix Q. A complete version of the post-test
from PD5 is in appendix J. The pre-tests and post-tests previous to that, while
not identical, are virtually the same. Obviously any questions about tissue
culture were not included in the PD5 final exam. Also, there were small
changes in wording to accommodate the particular conditions of each class.
As a result the total points possible on each test varied between 100 and 110.
Though 27 students comprise the study group, the total number of students
who took the pre-test and post-test in PD3, 4 and 5 is 29. Two students from
PD4 were also in PD5 because of AHS's small selection of course offerings.
They had not failed PD4. In so far as evaluating the null hypothesis is
concerned I have chosen to ignore that there were two repeat students. I
believe this approach is valid because students come to my classroom with a
wide variety of prior experiences yet I am evaluating them all according to the

same standards. I consider these students to simply be persons with a high

54

55

degree of prior topic familiarity. Also, the second pre—test gives some
information about long-term retention of PD information.

My hypothesis is that the instruction provided to students in PD3, 4
and 5 resulted in a gain of knowledge about the subject of microbiology as
measured by written pre-tests and post-tests. Conversely then my null
hypothesis is:

H0 = there is no difference between the mean pre—test and post-test

scores for students in the class, Tales From The Petri Dish.

n = 29
For the Pre -Test: For the Post -Test:
Mean (x) = 27.0345 Mean = 66.3621
Standard Deviation (sx) = 8.8297 Standard Deviation = 17.1604
First Quartile (Q1) = 21 First Quartile = 54.5
Third Quartile (Q3) = 31.5 Third Quartile = 77.25

According to Sincich (35) if the value obtained from the equation:

Inter-Quartile Range

Sx
is approximately equal to 1.34 then the data is normally distributed and a
valid student t-test may be run. The values obtained were:
Pre-test = 1.19

Post-test = 1.33

Sincich considers these values sufficient to run a student t-test. This means
that the null hypothesis can be rejected with a t value greater than 2.763 at the
0.01 confidence level and 28°of freedom. I ran a student t-test using the
equafion:

XZ-Xl

 

sxz . Jn—
and found that t = 12.3415

Clearly students in the PD classes learned some of the material. A
perusal of appendix Q will immediately explain the extremely high t value.
Without exception student performance improved. While some of the
poorer students nearly doubled their pre-test scores, increases by a factor
between 2 and 3 were typical. The two students, #6 and #11, who repeated the
class retained some of what they learned. Their second pre-test scores were
higher than their first pre-test scores by an amount approximately equal to
half of the increase between their first pre-test and post-test. Simply put, they

remembered about half of what they'd learned a year later.

11. Demographic Information About Students In Tales From The Petri Dish
Only those students who took both the pre-test and post-test are
included in my study group. As indicated in the introduction, students in PD

are some of the better students at AHS but in a traditional high school they

would probably rank much lower. The demographic data for individual PD

57

students (appendix R, S and T) supports many statements made in the
introduction. The appendices of demographic data are several pages in
length. I have supplied this much information to fill-out the readers mental
picture of my study group. All data comes from the students' CA-60 paper
files or the school's computerized attendance data base.

Appendix R lists information on PD students' age and Grade Point
Averages (GPA) at various points in time. The GPA information has some
trends worth noting. One, prior to attending AHS no students had an A or B
average, seven of twenty-seven had C averages and the rest were failing or
had D averages. 50 it is clear that even the better AHS students, those in the
PD classes, have a prior history of poor academic achievement. Two, the GPA
of all students increased at AHS prior to taking PD. Three, in comparing the
GPA at AHS of the 24 PD students in the semesters before and during the PD
class, thirteen declined while the others improved.

Appendix S shows attendance data. As stated previously only students
who took both the pre-test and post-test are included in the study. The second
and third column of appendix S show whether the student was present or
absent from my class and does not take into account absences that were
excused by the office. Some students that took both tests did not receive credit
for one or more marking periods during the class due to poor attendance.
Excused absences explain why several students with less than 80% attendance
received credit. Columns 4 and 5 are included in case the reader should be

interested in how long a particular student has attended AHS.

58

Appendix T lists grade level information and of the 18 students for
whom numerical data was available, 11 were at least one grade level below
their age group in at least one category at the time of the test. Of the
remainder, five students were at grade level and two were above. Michigan
Educational Assessment Program (MEAP) test results for secondary students
are reported by category: a student is said to be at a Low, Moderate or
Satisfactory level of achievement for their grade in school. Documentation
that I reviewed indicated that a student who receives a Moderate rating in
math is slightly below the standard set for students at this grade level. In
reference to the information in appendix T, I assume this means students
with Moderate or Low ratings were below grade level at the time of the test.
PD students graduating in 1994, 1995 and 1996 are required by state law to
achieve a certain score on the 10th grade math and reading tests in order to
receive a state endorsed diploma. Satisfactory or Moderate ratings in reading
or math allowed the student to receive the endorsement. A reading of the
MEAP results column in appendix T shows few students with any Satisfactory
ratings. The only two students who had two Satisfactories achieved this in
7th grade.

While 37% of the whole student body was in T0 at least once in the last
year, the rate was higher in PD5 students since seven out of thirteen or 54% of
these students were in T0. In the introduction a breakdown of the frequency
of T0 referrals for all students was shown. No PD students were in the group

that received 15 or more TO referrals but were almost evenly split between

59

the two groups with fewer referrals. The categories of offense resulting in
referral in decreasing order of occurrence include disturbing class, smoking,
not working in class, skipping, and drug possession. TO data is unavailable
for PD3 and 4 students.

In terms of their behavior, PD students are typical of the majority of
AHS students. They are not chronically disruptive. The offenses listed as
causes for referral are not violent or criminal actions or even unusual
behavior for adolescents. I see these students as making poor behavior
choices that are ultimately self-defeating.

PD students are typical of the student body as a whole in the dramatic
increase in GPA at AHS as compared with performance at their sending
school. I had hoped to see an increase in the GPA of PD students while they
were in the class so that I might say their motivation had increased but no
clear trend emerges from that data. Based on my experience, PD students are
slightly better than the majority of AHS students in attendance though I am
sure most of the percentages listed in the third column of appendix S would
be unacceptable in a traditional high school. With regard to academic
abilities as measured by standardized testing instruments, PD students
probably score higher than the average AHS student. Yet still about half the
PD students have skill deficits and most of the others have only average
abilities.

As stated at the beginning of this section the above information is

intended to fill-out the readers mental picture of my study group. I think it is

60

important for the reader to remember that while PD students might be better
than the average alternative student in some areas, they are still at—risk youth.
As a sidelight and possibly in reference to why these students are at-risk, the
two students with superior standardized test scores were referred to TO in 95-
96 five or more times. Only 25 students in the whole school were referred to

T0 more often.

HI. Analysis of Pre-Class and Post-Class Student Interviews

What follows is an analysis of student interviews conducted in PD5. Rather
than include the exceedingly lengthy verbatim transcript of student
responses, I have attempted to convey the spirit of their statements. Many
quotes are included as well as paraphrasings. Where it seemed appropriate
for clarity, student responses are in a list format. At other times lists of
student responses may be in paragraph form.

The pre-class and post-class interview instruments are contained in
appendix K. In the following analysis each question of the instrument is
referred to as an Item and is in a form relatively unaltered from that found
on the post-class instrument. I did not include the pre-class questions in the
analysis, only the pre—class student responses. The reader may generally
assume that information given is from the post-class interviews unless it is
indicated otherwise in the text.

In selecting the students to be interviewed I predicted their final

standing in the class based on my experience with them in previous classes. I

61

anticipated one would finish near the top, another at the bottom and the last
two in the middle of ranking by grade. Unfortunately the students I selected
were skewed toward the high end of the class. The class size was fifteen and
students I have designated here as A, B, D and C finished 1, 3, 5 and 10
respectively in grade ranking. The letters are arbitrarily assigned for the
purpose of clarity while also protecting student confidentiality. I selected
three males and one female because this reflects the male/ female ratio of the
class and AHS as a whole.

Students were encouraged to make extensive comments. To this end, I
did not pursue some points with students for fear of intimidating them or

altering their answers.

Items 1 and 2 were asked to put the subjects at ease. The information
requested was name, age, sex, place of birth, place of residence and name of

the class.

Item 3 - Was the class what you expected it to be?

Three students said yes and one said no but all of them reported
suprise at the inclusion of some topics in the course. Two of four students
reported suprise at the connection between food and microbiology. It made
sense to them now but they hadn't considered it before. A third student said
he expected only to cover bacteria and foods. The post-class interview

responses of all four students imply that they had expected to study bacteria

62

and other topics from the beginning. In their pre-class interview, however,
bacteria and these other topics were not mentioned. The same three students
said in the pre-class interview that they expected to use microscopes, do some
experiments and go outside to collect samples. I can think of two reasons for
this discrepancy between pre—class and post-class interviews. One, the
students had a vague understanding of what sorts of things might be included
in a microbiology course but lacked the vocabulary to verbalize what they did
know. Two, the students were not being entirely honest in their post-class
responses to please me. Because I made it clear to students that these
interviews had no affect on their grades, I tend to believe the discrepancy

between responses is caused by a combination of both things.

Item 4 - Are you glad that you chose this class or do you wish you had taken
another?

All four students were positive about taking the class. Students A and
C said "it was cool." Another said he liked learning things that were entirely
new for him. The fourth reported that he was considering pursuing field
oriented plant pathology in college. Three of the four students had chosen
the class because they had had me for class previously and/ or "it sounded like
fun." The fourth student (who was one of the two students who described
PD5 as "cool") had not chosen the class and was in fact quite negative at the

beginning because he had strongly preferred a different science elective.

63

Item 5 - List 3-5 things you did in this class.
Below is a list of student responses. The numbers in parentheses

indicate how many interviewees mentioned that response.

Enzyme experiments

Made a fungus garden (2)

Learned a lot about fungi

Went on many field trips (2) "to see how microbiology is used in the real
world"

Went on field trip to winery

Went on field trip to "sample. Chestnut Blight from the American
Chestnut"

Made beer (2)

Made yogurt (2)

Made sauerkraut

Learned sterile technique

Learned how to autoclave

Grew bacteria

Counted bacteria

Identified bacteria

Tested antibiotic resistance [of bacteria]
Answers to this question give an indication of what was most

memorable for students and there is a wide variety of responses. Perhaps this

indicates that the range of experiences structured into the class offers adequate

opportunities for student engagement. In comparison, the pre-class
interview responses were:

No idea

Experiments

Worksheets

Look through microscopes (2)

Crow and make our own penicillin

Collect samples outside

It seems the students have gained a broader, and at the same time, a more

detailed conception about the field of microbiology.

Item 6 - Were you excited and/ or interested in the following parts of the
class? Experiments / Field Trips / Information

In general, responses from two students (B & C) indicated they felt
more interest than excitement (these students preferred the experiments over
field trips and information), while the other two students felt more
excitement. Students D and B spoke at length. Student B reported this was
because he liked the "hands-on" experiments, getting to "set—up
experiments", and because he felt that he learned a lot. Part of what he liked
about learning was seeing "what the facts were" and the example he gave was
making beer. "I didn't know beer was made anything like that, with yeast and
all that stuff. I thought you took some barley and ground it up [then added

water and alcohol] from somewhere else. I didn't know it was made by the

65

yeast and all that." Student C also reported that she had learned new facts
about some things. The example she gave was the scale and technology of
commercial winemaking. She had been half-expecting to see people crushing
grapes barefooted.

As for the students who said they experienced a higher level of
excitement than interest, student D said this stemmed from the field trips
because "I get out and actually do it and visit the place where it's done."

Also, both students A and D were very clear that the notes and other
information were interesting because it aided their understanding. Student A
said "The notes helped me understand... It made everything else interesting
so in itself it was interesting."

In comparison with their pre-class interview responses, students B and
C showed a high degree of consistency between expectations and outcome in
all three parts of the class. Students A and D, however, reported changes in
attitude. At the pre-class interview student A had to be prompted twice to
describe his expectations before giving a sincere answer and that was a very
lukewarm endorsement of my ability to make learning "kinda cool." Student
D who was positive about the value of notes and information at the post-class
interview said at the pre-class interview that he hoped "they're not t_o_g

lame."

Item 7 - What is microbiology and what is usually considered to be part of it?

I treated this as a two-part question with students and have done the

same here. I have paired the pre-class (first line) and post-class interview
(second line) responses of each student to emphasize any changes in their
definition of the word microbiology.

A-Study of small things, microscopic size, bacteria and single cell organisms
A- The study of micro-organisms.

B-"Something to do with microscopes and microscopic animals."

B-The study of bacteria, fungi and viruses.

C-"It's where you're looking under a microscope."

C-The study of plant diseases, no, it's the study of life under a microscope."
D- Study of things you can't see with the naked eye, "algae and stuff like that."
D-"I believe that's ....the food thing", studying the micro-organisms involved.
I asked student D if there were anything else and he responded by vaguely
describing plant pathology and medical microbiology before finally recalling
and repeating the same definition he had given at the pre-class interview.

It seems that the later definitions given by students A and B are no
worse or slightly better than the first. However, the other two students leave
the impression that they are confused and I find this somewhat disturbing.
Their responses may reflect the fact that I did not overtly emphasize a
particular definition of the word and need to do that in the future.

Student responses to the second portion of the question were varied in
both length and content. Student C said "[mostly] the stuff we did in class"
while the others rattled off accurate examples of how microbiology is used

including mushroom culture, making medical diagnoses, food safety and

67

wastewater treatment. Because of a lack of academic success I think that
"alternative" students may feel more comfortable talking around a word
rather than defining it. All things considered I am satisfied that these
students have a fuller understanding of what microbiology is because of how

they discussed their examples.

Item 8 - What is a microbe?

I asked this question with the word microbe instead of micro-organism,
to three of the students. One said that the word meant the same as micro-
organism, another said they must have been absent that day and the third
said nothing. I asked the latter two if it would help if I used the word micro-
organism instead and both said it would. I did not think to pursue this
further, in retrospect I wish I had because it is an odd discrepancy that I would
like to understand. I assumed the words were as interchangeable for students
as they are for me. This is a point that I need to clarify in the next PD.

Item 8 a ~List types [of microbes]

Bacteria (4)

Fungi (4)

Viruses (3)

Yeast

Algae

Plankton

Very small insects

Cell Wall

Enzymes

These results are like a good news / bad news story. The good news is
that students gave the names of the two or three groups of microbes we spent
the most time on. However, the last three names given show an area that I
will need to clarify in the next PD. Student D suggested very small insects and
cell wall as microbes and in a way these items are consistent with his
definition of microbiology since one cannot see either with the naked eye.
Student A suggested enzymes yet did very well on the post-test. The enzyme
notes do not explicitly say that enzymes are not a lifeform, only that they were
originally discovered in living things. Perhaps he interpreted this thinking
that bacteria are also found in living things. Also, the series of enzyme
experiments in the PD introduction received less time but otherwise
comparable emphasis as the general information about fungus or bacteria. In
the next PD it will be useful to be more explicit about the definitions of

microbiology, microbes, micro-organisms and enzymes.

Item 8 b -List characteristics [of microbes]

Student responses were quite varied and included the small size of
individual microbes, that some are single-celled organisms (bacteria) and
some are not (fungi), that they absorb their food source through the cellular
exterior, that some are aerobes and some are anaerobes, that fungi produce

spores and are made of hyphae that get food and attach [to a substrate], that

69

they have identifiable shapes [and all the things we looked at in describing
colony morphology]. Each student said two or three of these things, but two
statements stand out for me. Student B said "That's one thing I learned in
this class. I thought they were all basically the same thing but they really have
a lot of different characteristics." I was pleased by his response seeing it as a
synthesis of information. Student C said "most infect something." I am fairly
sure that I said no such thing if for no other reason than that it is probably not
true. However, her response shows me another possible misconception that
needs to be explicitly addressed next time.

Responses in the pre-class interview emphasized the small size of
microbes and to a lesser extent that microbes are unicellular. My conclusion
then is that there was growth in the richness and variety of student
understanding.

Item 9 - who uses microbiology and how?

 

I asked this as three separate questions where the underlined words
shown below would be inserted in the blank. Under each are a sample of the
responses.

Item 9a - In General

All post-class interview responses were in the area of medicine and
health. They included disease identification, research, anyone who works in
a hospital or around [the young of any species], blood analysis for cell counts

and drugs, producing antibiotics, culturing pathogens to test the value of

70

antibiotics.

The pre-class responses were: marine biologists, the Upjohn
pharmaceutical company, hospital medical technology labs, biologists, disease
control officers, doctors and "in wastewater treatment (2)". If anything there
was somewhat more variety in the pre-class responses. This is to be expected
because I did not include any sort of general survey of the uses of
microbiology outside of the topics the class emphasizes. The question was
included simply to see what students would say.

Item 9b - In making or studying foods

One student listed brand names but the others simply said producers of
some or all of the four foods that we made plus cheese and bread as well as
mushroom growers. In answering how microbiology is used in producing
these foods, all four students gave detailed and accurate examples from either
the Campbell's Fresh or winery field trips. In the pre-class interview two
students could not think of any uses while another said micro-organisms
cause food to decay and the last student talked vaguely about how he thought
companies produced sour cream using microbes and that all food producing
companies would check to see if foods are contaminated. Again, there is a
richness to the post-class interview answers that was absent before.

Item 9c - In studying plant diseases

In the post-class interview, Student C could not think of who or how

anyone might use microbiology in studying plant diseases other than to

repeat that professors from M.S.U. had come to see the very large American

71

Chestnut at the edge of town. Students A, B an D all suggested various
persons in the agricultural field - farmers (2), [agronomist], tree farmers,
F.D.A. vegetable inspectors and Michigan D.N.R. preserve managers charged
with the responsibility of monitoring general forest health. One particularly
perceptive answer was that importers should be aware of microbiology so that
they wouldn't bring in a different microbe that would "wipe out a whole
species of ....whatever." In the pre-class responses two students had nothing
to say, a third thought a botanist might use microbiology and student D knew
that "mushrooms that grow off the sides of trees is a disease." He also
wondered if maybe mosses weren't also a plant disease.

Given that foods and plant pathology were the two special areas
emphasized in the class I find the growth in their answers for these questions
satisfactory. In the next PD it would be beneficial to students to include in the

class introduction a survey of the whole field of microbiology.

Item 10 - What ideas did you learn from this class and/ or How has taking this
class changed your view of the world?

I found these student response to be the most gratifying. Assuming the
students were sincere, and I have no proof to the contrary, they gained some
profound insights from what they studied. Student A described at length
how he made the connection between hearing about something (i.e., a place,
invisible microbes) and having it truly exist for him. "if I go over there and

grab that doorknob, what's gonna be on it [so] you realize there's more to the

72

world than just what you can see. Maybe it might not just be the small things
you can't see [it might be] other cities, other countries."

Student B reiterated the caution that he felt an importer should
exercise and added that if he were an importer he wouldn't want to be
responsible for bringing about the end of a plant, such as corn, that is so
important to the survival of millions. On a more personal level he added "I
have a baby on the way [so I] go through a little more cleaning of stuff because
bacteria can be spread so easily....you touch something one place and touch
another place and it's like 11333!"

Student C reported that the class experience had affected her food
choices. For example she won't eat sauerkraut now because it is
unrefrigerated so long as it ferments and to her that seems unsafe even
though she knows better. On the positive side she says she is more open to
trying some homemade things, like ginger ale. Also, student C mentioned
gaining a new appreciation of the value of the American Chestnut.

Student D discussed his heightened awareness of the value and
vulnerability of plants - "Nobody wants a barren ugly world....[I just realized]
how susceptible trees are." in addition he was impressed by "how important
plants and micro-organisms are to the economic system. As in the food
thing, if we didn't have certain types of bacteria or fungus we wouldn't have
certain types of food."

These comments are more thoughtful than what I am accustomed to

hearing from AHS students. In their pre-class responses students either had

73

no idea what to answer or suggested things that would more appropriately be
called skills. It seems valid to attribute some positive impact by the class on

the students level of awareness.

Item 11 - Name 3-5 skills you have learned from this class.

Basically post-class responses to this item were a reiteration of what
was said for Item 5. Since their responses were stated as skills not as things or
activities, the interviewees were making a distinction that I feel shows they
understand the word as it relates to microbiological skills. I would have felt
they had missed something if they had not made that discrimination. One
student maintained he had never used a microscope before. Responses
continued to affirm the trend of richer and more varied answers as compared

with pre-class responses.

Item 12 - Did you learn any skills or information from this class that you will
be able to use in:
Item 12 a - the real world

Responses centered around possible uses in the home or garden such
as improving hygiene for self and/ or infants, food production and dealing
with garden diseases. One response I liked was "how to treat the world" in
reference to not transporting new pathogens or exotic species. In the pre-class
interview student D was the only one to respond and he said others could

find cures for the most important diseases.

74

Item 12 b - a future job

Three students could see potential applications of PD skills and
information in the careers in which they are interested The fourth, student
D, says he is interested in pursuing plant pathology as a career. In the pre-
class interview student A thought it was a remote possibility and the other
three could see no applications in the careers they wanted to pursue.
Item 12 c - a later science class

In the pre-class interview three of the students said that if they went to
college and took biology classes, then the PD skills and information would be
valuable. In the post-class interview these same three students indicated a
greater willingness to include, or in one case emphasize, biology classes if they
attended college. Student D, the student who is now interested in pursuing
plant pathology, had no response at the pre-class interview. He believes
having the PD class on his high school transcript will be useful and that the
skills and information will be useful in his course work.

In all three areas of Item 12 post-class responses were much greater in
number. I would assume from this that for the most part students see

usefulness and value to what they learned in the class.

Item 13 - Do you think it is valuable to simply have general knowledge (such
as how cheese is made) that you may not use in the real world, a future job or
a later science class?

Students B, C and D said yes to this question in the pre-class interview

75

and reported no change in their attitudes after the class. However, as with
responses to several other questions, post-class interview responses were
more lengthy and descriptive. I am not sure why that is, perhaps they
became more comfortable with me or perceive the PD classroom as a place
where they can "be smart" with less criticism from others. Student A's pre-
class interview response was "not really" His post-class interview response
was a lengthy explanation of knowledge being power and how that might
apply in his life. I don't believe he learned all of that from studying

microbiology, so I assume he is just more comfortable.

Item 14 - Now that you have taken this class would you consider a career in
science or a related field?

As in Item 7, the pre- and post-class responses of each student are
paired. After each set of responses are cements regarding my interpretation
of the effect of the PD class on their attitudes toward future employment.

A-" Yes, I want to be an astrophysicist."

A - Unchanged

Student A is a freshman and quite intelligent but he has very low self-esteem.
His mother took an evening astronomy class at a local two—year college and
usually brought him along. The instructor treated student A well and used
him in classroom demonstrations. I think his interest in astrophysics stems
more from the respectful treatment he received than interest in the subject.

Student A does very well in science classes and may very well work in science

76

or a related field if he sorts out his difficulties but PD does not appear to have
caused a significant alteration of his attitudes toward future employment.

B - "Probably not"

B - "Not immediately, but down the line [if things came together] I'd
definitely at least think about it."

Student B was a sophomore this past year, expects the birth of his first child
this summer, is a gang member and is currently on an electronic tether for
firearms charges dating back two years. Student B is also intelligent,
perceptive, polite and a pleasure to be around. Given the difficult situation in
which he currently finds himself, B may be considered as doing well in the
future by responsibly raising the child he will soon have and supporting it
with legitimate employment. I do believe that B was sincere in his post-class
comments and I think PD may have had some role in that change of attitude.
C — "No, I want to go into computers" [ as a secretary]

C - Still most interested in secretarial but would now at least consider it
especially if the two could be combined.

Student C will probably graduate next year and become a secretary. I do not
see that PD has had a significant impact on her career choices.

D - Yes, I might work in a wastewater treatment plant or in the factory at
UpJohns.

D - Is interested in pursuing plant pathology as a career

While Student D expresses these desires with reasonable confidence of their

attainability I am not so confident. His verbal skills are poor and his level of

77

motivation is at times quite low. Also, his attraction to plant pathology may
have more to do with a perception of it as a field where one spends
considerable time outdoors than a deep interest in the subject. On the
positive side however, he has usually done well in science classes, as he did
in PD, and he did graduate this year. I will say, with reservations, that

participation in PD has affected his choice of potential careers.

Item 15 - In the pre-interview you said (Answers varied__) about science
classes in general, has this class changed your feelings about that or how do
you feel about this class compared to others you've taken?

All students reported no attitudinal change. Students A, B and D had
positive feelings about science classes before and after PD. Student C is still

weakly positive about science classes.

CHAPTER 5

CONCLUSIONS

What Was Effective In TALES FROM THE PETRI DISH?

As mentioned earlier, I believe the results of the student evaluations
are accurate reflections of student opinion. In the following discussion of
what was effective and what needs improvement I will frequently refer to the
ratings or values that students gave to the experiments and field trips. The
student interviews are also an important source for this discussion.

I asked all PD5 students to rank, in order of preference, the five main
units of the PD class after they were finished evaluating the labs and field
trips. In retrospect, I think it would have been valuable to treat enzymes as a
unit so that it would be included in this ranking. The ranking from most to
least liked was:

Food Microbiology
Fungus

Bacteri

Plant Pathology

Sterile Technique

78

79

One of the most successful aspects of the PD classes is how much the
students learned. Even students who failed the class or had poor attendance
improved their scores and most improved by a factor of two or three.
Contrasted with pre-test/ post-test score comparisons from other classes I have
taught at AHS, these are phenomenal gains. In nearly all interview questions
that were intended to measure the students concept of the size and contents
of the field of microbiology, responses in the post-class interviews were
longer and more detailed than those of the pre-class interview. I have no
hard data to back it up, but my feeling is that most PD students felt pride in
themselves for learning so much about a new and challenging subject. It is
possible to teach a quality microbiology class to at—risk teens and it is possible
for them to succeed in the class. I have no doubt that some of the special
atmosphere of these PD classes happened because the students knew this was
important to me so it became important to them. The challenge will be to
replicate that sense of importance in future PD classes without the
motivation of thesis research.

Positive attitudinal changes were brought about by the class. In
responses to Item 12 b students indicated they could now see some possible
applications of microbiology in future jobs where they saw none before. In
item 14 two of four students definitely exhibited a positive change toward
consideration of science or a related field as a career. Described in Item 10
were the insights leading to a new world view that students attributed to the

PD class. Pleasing on a personal and professional level is the concern shown

80

by students for the American Chestnut and it's struggle with chestnut blight.
I have rarely stimulated as much concern about any environmental issue in
other classes. All of the interview students mentioned the Chestnut or blight
in one context or another, including student B's thoughts about the
precautions that an importer should take.

I am generally satisfied with the selection and arrangement of units in
the class. I feel that it worked well to lay groundwork by covering enzymes
and sterile technique at the beginning of class. Even though some students
may think that enzymes are organisms, most students do seem to understand
the importance of the role that enzymes play in life-sustaining microbial
processes. Though learning sterile technique was the least liked unit I can
hardly drop it. Perhaps ways to make it more challenging should be found. I
feel some disappointment that plant pathology was less well liked than
bacteria and fungi. However, considering the lack of closure on some of the
experiments, I am not surprised. Certainly this is one area of the class that
requires fine tuning.

Brewing beer was probably one of the smarter choices that I made in
designing the course. It ranked first in student interest and did well in the
other two categories. Beermaking was one of four things (out of a total of 15)
to be mentioned by two students for Item 5. Brewing probably has much to do
with food microbiology being the most-liked unit.

Students reported that they both liked and learned from the field trips.

Results of the student evaluations show that out of the twelve values for the

81

field trips (three questions multiplied by four field trips) five were above 0.90
and the rest were 0.83 or above. This means that not only was the interest
high but that in all cases students felt they understood what was going on and
that it helped them understand classroom material. What I might typically
hear from students about field trips in any other class is that they are just
happy to "get out of class." In PD, students did indeed "get out of class" but
they were writing reports about the trips so their interest was not simply from
the fun. The field trips were mentioned in responses to most questions
during the student interviews. Effects mentioned there range from
challenging student preconceptions to stimulating student D's interest in
plant pathology as a career to seeing unique things for the first time.

Prior to PD5 I had never done interviews with students. The time
required for all phases of the process - preparation, interviews, extracting data
and interpreting data - is considerable. However, I learned things from the
interviews that I would not have known otherwise. These include factual
misconceptions such as the students who listed enzymes, cell wall and very
small insects as types of microbes. Clearly these are points to address in the
next PD. Also, through the interviews I get a much better sense of how my
students think and what parts of the class are significant to them. Another
aspect of the interviews is positive reinforcement of the instructor. On the
whole, what went on in the PD class was good and the interviews reflect that.

Compared with my other upper-level class, Stream Team PD requires

 

a much greater amount of planning and making arrangements. But with

82

some exceptions most of the things I tried to do with the class worked well
enough to be called successful. For example, arrangements for the four field
trips, which only consumed four of the 80+ days of class, include finding
suitable destinations that tied into class content, scheduling times and dates
with the people at the destination, arranging transportation, permission slips,
writing report forms, preparing for discussions about the trip before and after
it occurs. But as I discussed in a previous paragraph the field trips were a very
successful aspect of the class.

I found it exciting to explore what may be new territory in regular high
school classrooms and certainly is in alternative classrooms - teaching plant
pathology using experiments about chestnut blight and the resistance of

cucumbers to disease.

What Needed Improvement In TALES FROM THE PETRI DISH?

As stated above, the food microbiology unit was ranked by students as
the one they most liked and that brewing beer was the most popular of the
four foods produced. It is less clear which of the other foods is the least
popular. There are statements in the student interviews that could be
interpreted as for or against producing yogurt, ginger ale and sauerkraut. In
the student evaluations making ginger ale is 0.17 to 0.19 points ahead of
making yogurt and sauerkraut. At the Microbiology Meal of PD4 the

sauerkraut was uneaten, ginger ale was tolerated and the nearly all of the

83

yogurt was consumed. I suspect that the context had more to do with these
inconsistencies than the foods themselves.

There are three possible ways to alter this situation. One, don't
produce any foods except beer. I don't like this solution because I think the
variety of products is valuable for student understanding and allows greater
opportunities for students to find something that appeals to them. Two,
substitute other foods for yogurt, ginger ale and sauerkraut. Beyond cheese
and pickles, I am not sure that there are other foods produced by microbes
which would be familiar to my students. Also, both cheese and pickles
require long processing times and given the difficulties already experienced
with experiments that span days, I don't need to add another long-term
project. Three, change the context in which these three foods are presented.
This is the solution that most appeals to me is since it builds from what I
already have in place. Future classes could have fun by making semi-
recreational time in class to taste foods as soon as they are ready. For example,
we could grill hot dogs and bratwursts to put sauerkraut on or use a variety of
toppings to mix in with yogurt. I did not overtly schedule this time in
previously because I assumed that the students would automatically take care
of eating the foods.

By far the greatest difficulties in the class were issues of time. There are
three aspects of this that I would like to address. One, some of the plant
pathology experiments were not completed because not enough time was left

at the end of the course. Two, some of the projects that involved leaving

materials for a period of days after the initial set-up were not returned to in a
timely manner. Three, considering all factors, what length of class period and
what total class length should I request the next time PD is in the AHS
schedule.

Since PD5 did not include the unit on tissue culture and was taught
over a period of sixteen weeks as compared to the nine weeks allowed for PD3
and 4, one would assume that the plant pathology experiments should have
been completed. The primary reason why they were not is that I asked for
much more in the way of written work from the PD5 class, especially in the
units of the class prior to food microbiology. Probably five or six times as
much written work was required in PD5 as compared to PD3 or 4. That was
especially time consuming given the skill levels of my students. Also, many
of the papers were revised by students and resubmitted. The question must
be asked: Was all the writing worth-while and was it worth not completing
some of the plant pathology experiments? I do believe writing by students is
worth-while in all subjects. However, I don't think the quantity of writing
requested should prevent the timely completion of experiments. I believe
that the writing probably led to greater student understanding, but I have no
data to support that belief. Also, I imagine that the amount of writing
required and that I asked for revisions is part of why students felt that the
course was important to me (as discussed above). I do not intend to drop
plant pathology from future versions of PD so writing in the earlier portions

of the class must be curtailed somewhat. Additionally, I could drop one or

85

two of the less popular and / or less effective labs intended to introduce
enzymes and basic information about bacteria.

The problem of revisiting experiments days after the initial set-up does
not have so obvious a solution. Experimental projects that have a higher
degree of interest for the students, such as brewing, were less often
overlooked. For my part, I tended to focus solely on the experiment at hand.
Perhaps greater experience with these experiments will better enable me to
step back to see the big picture and arrange for students to revisit the
experiments. Another solution for the near term would be to designate a
student or students whose responsibility it would be to keep track of all the
experiments currently being conducted.

Next year AHS will be in a different building and the program has been
downsized from nine to six teachers and by 20 or more students. It is not clear
yet whether we will be able to offer anything beyond the basic two years of
biology and physical science required for graduation. Also, the trend at AHS
over the last few years has been away from block classes. This past year I was
the only teacher to have block classes all year and next fall I won't have any
because it makes scheduling students difficult. The flexibility allowed by
having 110 minutes with students each day has been an important part of PD.
The nine week length of PD3 and 4 was too short for all that I tried to include
in the class. With good organization and a reduction in the number of labs in
the first portion of the class, I think it may be possible to offer PD as a one-

semester class that meets one hour per day five days a week.

The most basic question for any educator must be "Is this good for the
student?" because nothing else matters as much. T_ales From The Petri Dish
was definitely good for the students in my classes. They saw things that were
entirely new to them, they were challenged by the material and they had
enough opportunities with all the different experiments to find something
they liked. Certainly there are portions that could be improved but I think it
is possible to meaningfully teach microbiology to at-risk high school students.
One young mother who was not an excellent student and missed 24 days
during the class said she was taking the post-test "You ought to be proud of
yourself because I feel like I really learned something in this class. I usually

don't feel that way when I'm taking a science test."

87

BIBLIOGRAPHY

1) Anderson, Charles W. January, 1994. Teaching Content in a Multicultural
Milieu. To be published in Zeitschrift fur Padagogik.

2) Anderson, Charles W. January, 1993. Special Education Trends and Special
Education.

3) Anderson, Michelle. 1994. Conversation regarding research possibilities.

4) Anagnostakis, Sandra L. January, 1982. Biological Control Of Chestnut
Blight. Science [215]: 466-471.

5) Bottino, Paul J. 1976. Introduction to Plant Cloning I. Kemtech Educational
Corporation. Manual for kit.

6) Brockman, Ellis R. 1980. inzLaboratory Manual For Microbiology, 2d
Edition. Pendell Publishing Co. pp. 49-50.

7) Brown, Tom. Yeast Population Studies Of Brewing Soda Pop. in:Cellular
and Molecular Biology handouts. Unpublished.

8) Burns, Caroline. January/ February 1984. Saving This Fine Tree. Michigan
Natural Resources. pp. 27-33.

9) Corner, Tom. inzLaboratory Manual For Microbiology. Department Of
Microbiology, Michigan State University. pp. -189.

10) Crowley, Rose Lea and Wm. H. Weston. 1968. inzTeacher's Guide For
Microgardening. Webster Division of McGraw-Hill Book Company. pp. 12-55.

11) Fleming, Michael F. 1993. inzBiology Teacher's Survival Guide:
Techniques and Materials for Success in the Classroom. Center for Applied
Research In Education. pp. 142-155.

12) Fleming, Michael F. 1992. inzFocus On Microbiology. Center for Applied
Research In Education. pp. 168-180.

13) Frey Scientific Company Staff. 1976. Bacteria Stain Kit Manual. Frey

Scientific Company.

14) Fulbright, Dennis. July 1993. Environmental and Behavioral Biology
Workshop.

15) Gillen, Alan L. and Robert P. Williams. May 1993. Dinner Date With A
Microbe. The American Biology Teacher [Vol. 55, N o. 51:268-274.

16) Haack, Sheridan. October 1992. Microbial Ecology, a Frontiers Workshop.

17) Hagerman, Howard. Fall/ Winter 1988/ 1990. Demonstrating Plant Tissue
Culture Using Two Plant Hormones. Natural Science: 13 - 15.

18) Haldemann, Janice and Jane P. Ellis. March 1988. Using Cauliflower to
Demonstrate Plant Tissue Culture. American Biology Teacher [Vol 50, No 3]:
154-159.

19) Ham, Fred L. February 1993. The Bacteriology of Yogurt. in:Kitchen
Chemistry, a Frontiers Workshop. Unpublished.

20) Ham, Fred L. February 1993. Ginger Ale Fermentation. in:Kitchen
Chemistry, a Frontiers Workshop. Unpublished.

21) Ham, Fred L. February 1993. Milk, Galactose and Galactase. in:Kitchen
Chemistry, a Frontiers Workshop. Unpublished.

22) Ham, Fred L. February 1993. Jello and Pineapple. in:Kitchen Chemistry, a
Frontiers Workshop. Unpublished.

23) Ham, Fred L. February 1993. Studies of Fermentation In Sauerkraut.
in:Kitchen Chemistry, a Frontiers Workshop. Unpublished.

24) Hammerschmidt, Raymond. March 1993. Mechanisms of Disease
Resistant Plants, a Frontiers Workshop.

25) Hammerschmidt, Raymond. 1994. During On-Campus Research Period.

26) Hammerschmidt, Raymond and P. Yang-Cashman. 1995. inzlnduced
Resistance to Disease in Plants. Kluwer Academic Publishers. pp. 63-85.

27) Headon, Denis. 1982. Enzymes in Industry. Kemtech Educational
Corporation. Manual for kit.

28) Hill, Stanford R., Jr. and Paul B. Hounshell. March 1991. Summer School
Remedial Biology - An Innovative Approach. The American Biology
Teacher[Vol 53, No 3]:176-178.

89

29) Lapointe, Archie, J.M. Askew and NA. Mead. 1992. inzLearning Science.
Educational Testing Service. pp. 20-70.

30) MacDonald, Wm. L. and Dennis W. Fulbright. July 1991. Biological
Control Of Chestnut Blight: Use and Limitations Of Transmissible
Hypovirulence. Plant Disease [Vol. 75, No. 71:656-661.

31) Mangino, Richard A. 1975. in: A Laboratory Manual For Microbiology. J.
Weston Walch, Publisher. pp. 47-50.

32) Newmann, Fred M., Gary G. Wehlage and Susie D. Lamborn. 1992.
in:Student Engagement in Amercan Secondary Schools. Teachers College
Press. pp. 11-39.

33) Pelczar, Jr., Michael J., E.C.S. Chan and Noel R. Krieg. 1986.
inzMicrobiology, 5th Edition. McGraw-Hill Book Company. pp. 649-658.

34) Seeley, Jr., Harry W., and Paul J. VanDemark. 1981. in: Microbes In Action:
A Lab Manual Of Microbiology, 3rd Edition, W.H. Freeman and Co. pp. 17-18,
22-23, 42-48.

35) Sincich, Terry. 1992. in: Busines Statistics By Example, fourth edition.
Dellen/ Macmillan Publishing Company. pp. 265-268 8: 500-501.

36) Steele Claude M. April 1992. Race and the Schooling of Black Americans.
Atlantic Monthly. pp. 68-78.

37) Tobias, Randolf. inzNurturing At-Risk Youth in Math and Science.

38) Vatter, Terry. April 1992. Teaching Mathematics to the At-Risk Secondary
School Student. The Mathematics Teacher [Vol 85, No 4]:292-294.

39) Yager, Robert E. February 1993. Make A Difference With ST S. The Science
Teacher. pp. 45-48.

APPENDICES

90

APPENDIX A

MICROBIOLOGY IS... & STERILE TECHNIQUE

W ------

l-The study of organisms visible under a microscope and anything else about them including
their culture, economic importance, pathogenicity, etc.
2-Microorganism and microbe mean the same thing - organisms not visible to the naked eye
3-The Main Groups of Microbes include the following

Bacteria

Fungi

Algae

Viruses

Protozoa

SI ERILE TECHNIQUE IS ......

Number 1 requirement to keep you healthy and for consistent success in microbiology (by
preventing contamination of the desired microbes with undesirable organisms)

BASIC CONCEPTS
Usually we are trying to have only the stuff we are studying grow in a container

There are gazillions of bacteria and fungal spores in the air and on everything (especially your
hands) just waiting to "hatch out", that's a good and bad thing
GOOD BAD

1;!th

Flaming - passing an object through flame until it is red-hot allow to cool
Boiling - in rolling type boil if all surfaces open for 10 min.

Baking

Autoclaving - pressure cooker, dangerous if handled improperly

Steg’lizing Liquids
Alcohol (70%)
Bleach in low concentrations (5-15%)

lnverting Dishes -

Invert means to turn upside down
The purpose is to keep liquid that condenses away from media surface

0 ' etri '3
Open it only as far as is needed but far enough that you can safely work on the dish
When it must be entirely lifted off the cover should be held above the plate

Petri Dish Transfer
Flame the NiChrome Loop, Allow to cool

Dip loop slightly into what's being transferred
Touch loop to second plate
Flame loop, repeat, repeat, repeat

91

Keep things covered -particles in air (including bacteria) most often fall down
Cut down the flow of air for example - outside air to a more sterile area
Most of all think about what you are doing and take appropriate precautions - SAFETY FIRST

WORKBENCH HYGIENE

Cleaning area - use paper towel or sponge to spread a 10% chlorox solution, before & after using
a tabletop

Discoloration of clothes due to contact with liquid bleach is possible if you're not careful

Proper disposal- anything we make with bacteria or fungus should probably be placed in
sealed "BIO-HAZARD" bags

Dangers of breathing -BE CONSCIOUS of what we're working w/ chemicals, fumes, bacteria
may be inhaled, get past immune defenses and cause a problem

Eating/ drinking - not at tables or maybe even in room when we are doing an experiment

WORKING ON MEDIA

Media is the name for the material on/ in which a microbe is grown
-The media used in petri dishes is generally a gelatin-like substance (agar) with
various additives such as nutrients, pH indicators and much more!!!!
-A liquid media (called broth) may also be used.

ST REAKING
-to just transfer (1)
-to isolate one organism (1-2-3)

 

 

 

 

 

 

 

 

 

 

PLACING
-to fit several transfers onto one dish

92

APPENDIX B

ENZYMES NOTES
Enzymes:
-they DO things by helping chemical reactions happen lots faster and easier
usually without enzymes the reaction would require high temperatures &/ or
extreme pHs

-enzymes are not used up in the chemical reactions so a little enzyme helps
lots and lots (but they do wear out in weeks or months)

-enzymes are made by and were originally discovered working in organisms
but can work outside organisms
[Louis Pasteur yeast fermentation (glucose to ethanol & COz)]

-enzymes are found in all organisms, life is not possible without them BUT
ENZYMES THEMSELVES ARE NOT ALIVE

-most enzymes only work to make just 1 chemical reaction happen (there are
19 chemical steps in changing glucose to C02 and water, each step requires it's
own enzyme)

-they are a type of protein but they are not a nutrient and are not digested
-heat will "denature" or wreck an enzyme

-names of enzymes usually end in "-ase"

-concentrations of enzyme and substrate affect the speed of enzyme reactions
as do temperature, pH and the presence of inhibitors

Substrate + Enzyme --> Enzyme-Substrate Complex --> Products + Enzyme

 

93

APPENDD( C

BACTERIA NOTES
1) WHAT THEY ARE
a-probably the first form of life on the planet

b—they have no internal membranes, insides of cell very simply organized

c-some are photosynthetic, most "eat" living or dead unicellular or
multicellular organisms

d-they eat by chemical reactions, they will use any reaction that produces
energy and only reactions that produce energy

(sugar)
Example Glucose + Oxygen -->Carbon Dioxide + Water + Energy
C6H1206 C02 H20

in digesting sugars, bacteria gets C, H 8: O to "build" new cell parts and the
energy to do it with

2)Reproduction
a-reproduce very fast, average doubling time is 20 minutes.

b-reproduce by simple cell division. Contents of cell are split evenly, pushed
to either end, middle pinches in to form 2 cells

—> (2%?) ——- ® @

c-each species of Bact has a maximum cell size, when it gets that large it
divides
d-bacteria can also form spores to survive heat, drought, poisons, etc.

3) WHERE THEY ARE

a-Bacteria live under all imaginable conditions, bacteria are everywhere
Antarctica to thermal vents, pH 2 to pH 13, soil, air, water, etc

b—the weight of bacteria in the average human body is about equal to the
weight of 12 oz. can of pop

4) IDENTIFYING BACTERIA
a-AEROBES take in oxygen to "breathe"
ANAEROBES "breathe" other gases - methane, ammonia, etc.
b-CATALASE or REACTION
-amount of bubbles produced shows how much enzyme is present

94

c-Typgs Grouping
chains COCO

a-Shapes
cocci (spheres) 0 sheets %

spirilli (corkscrews) a)
clusters

bacilli (rods) C)

c-GRAM STAIN

-describes the ability of a bacteria to hold gram stain in their cell membrane

-positive bacteria hold the stain, negative do not

-depends on 2 things -thickness and material of the membrane
-pore size

-generally different antibiotics would be used on each group

-UV light makes free radicals, which tend to break things apart (example:
collagen fibers in skin, as they are broken skin sags & gets leathery - aging!)

-the enzyme makes free radicals safe to organisms

-Hydrogen Peroxide is not in body, it just acts like free radicals so enzyme
attacks it and makes it into water and oxygen

e-COLON Y APPEARANCE

-one single bacteria after reproducing for a time will become a group of
several million that is visible

-visible characteristics can be observed and classified (see Cultural
Characteristics of Bacteria chart)

Comparing How You Study MacroOrganisms 8r Micro-organisms

Macro-organisms Micro-organisms
-body and behavior are important -metabolism & physiology are imp
-genetic exchange is restricted -genetic exchange is lei restricted
-can see their environment -exact conditions of their environment
is hard to see
-can easily see differences -must often "test" for differences
HOW HARD IT IS TO KNOW SOMETHING ABOUT AN ORGANISM
MICRO-ORGANISMS MACRO-ORGANISMS
DISTRIBUTION
HABITAT
easier INTERACTION easier
GENE POOL
GENETICS

GENE EXPRESSION

95

Appendix D

FUNGUS NOTES

STRUCTURE
Hypha are the long strings of fungus cells that do the regular job of living for
a fungus such as eating and growing.

The mycelium is a group of hypha where there are enough hypha to see with
the naked eye.

FUNGI have a cell wall made of CHI'TIN, this protein is most often found in

one other group of organisms -> INSECTS. Their hard shells or exoskeletons
are also made of chitin.

EUKARYOTES - fungi have internal membranes, unlike bacteria. Some types
though do not have separations between cells.

TYPES - Examples of fungi include

Yeast Slime molds
Mushrooms Puffballs
Molds Most plant diseases

Bracket fungi

REPRODUCTION AND GROWTH

- A new mycelium can start growing in a new places by the transfer of spores
or pieces of hyphae.

- Spores have hard thick walls so they can survive bad conditions. Hyphae
cannot

- Spores can be produced by sexual or asexual means. Yeasts asexually
reproduce by budding.

- Growth is by simple cell division.

NUTRITION

- Though they may look like plants, the fungus is eating it's food by making
acids and enzymes to dissolve the food source and then absorb the food
through the cell wall and cell membrane.

-Fungi eat living (parasite) or non-living (saprophyte) materials

-Because of their ability to make strange and powerful chemicals, fungi can
live on and eat many strange things.

96

Appendix E

FOOD MICROBIOLOGY NOTES
The purpose of both fermentation and respiration for micro-organisms is
to produce energy. They happen to produce by—products that we like - alcohol,
acids, carbon dioxide, curds, etc.

Most foods produced using microbes involve fermentation.
Most beverages produced using microbes involve fermentation.
Fermentation does not always results in the production of alcohol.

When a micro-organism is used to produce a food or beverage, it "eats" raw
material(s) using enzymes and then makes a desired product

For Example: Lactobacilli use lactase to digest lactose and are used by the food
industry to make sauerkraut (proprionic acid) and yogurt (curds).

All production of beer and wine depends on the many species of the YEAST
fungus.

Microbes eat by any chemical reactions that produces energy and only
reactions that produce energy in digesting sugars, microbes gets C, H & O to
"build" new cell parts and the energy to do it with

(sugar)
Example Glucose + Oxygen -->Carbon Dioxide + Water + Energy
C6H1206 C02 H20

SEEN THIS BEFORE????????
You should remember it from the bacteria notes. This is the chemical
formula for respiration but fermentations work in almost the same way.
Other things will take the place of the Oxygen and maybe for the Water and
Carbon Dioxide. Sooooo ......
Fermentation doesn't require Oxygen (anaerobic)
Respiration does require Oxygen (aerobic)

Photosynthesis and respiration are the ~reverses of the same chemical
process/ equation. See if you can write the photosynthesis equation!!!”

As we go through the experiments describe below which micro-organisms are
doing what with what and how that results in the desired product.

a)Cabbage and Salt into Sauerkraut

b)Hops, Malted Barley 8: Water into Beer

c)Granulated Sugar, Lemon, Ginger, Tartar into Ginger Ale

d) Milk into Yogurt

97

Appendix F

PLANT PATHOLOGY

DO YOU HAVE ANY IRISH ANCESTORS? THEN THIS STORY SHOWS
WHY YOU'RE HERE.

Irish Potato Famine - 1840's

Warmer winter followed by a normal (mostly) warm growing season but late
summer turned cool and rainy.

Leaves and stems seemed to "melt" away as they rotted and the potatoes were
rotten and smelled WAY BAD!

Count DeBary saw white fuzz on leaves of sick plants which he knew meant a
fungus was present, and wondered if there was a connection to the disease.
EXPERIMENTzHad potato plants in cold wet conditions
Half the plants had fungal spores,
half were kept from any spores.
Only those with spores got disease.
WHAT DOES THIS PROVE?

There are 3 CONDITIONS FOR A PLANT TO GET A DISEASE

-must have a PATHOGEN present

-must have proper ENVIRONMENTAL CONDITIONS

-host plant must be SUSCEPTIBLE (= can catch disease)

(Of 10005 of plant diseases 1 species of plant will only be
susceptible to 10 to 20)

DO YOU SEE THE 3 CONDITIONS IN THIS STORY?
{Millerdent-Bourdeaux mixture, discourage poachers, copper shell casings in
the 1840's)

THE PATHOGENS

FUNGUS ARE THE WAY MOST IMPORTANT!!!!!!!!! 80% of Diseas_es_
Examples - Rusts, smuts, Dutch elm disease, Chestnut blight, black

bread molds, storage rots of fruits and vegetables, leaf spot, Black scurf (on

potatoes)

BACTERIA are second

Examples - Lilac leaf spot, Soft rot (squishy potatoes in the bottom of
the bag WHY? - the bacteria has made enzymes that digest pectin, freed sugars
and other goodies are absorbed by the bacteria.

VIRUSES ’
Example - Tobacco ring spot - you've seen it on watermelon
and cantelope

98

HOW PATHOGENS ATTACK AND PLANTS FIGHT BACK

FUNGI-
1)spore lands in good spot on outside of plant

2) spore grows a germ tube, an appressorium (glued on), then HYPHAE
which begin eating it/ their way into the plant

3) Usually plant doesn‘t react until hyphae reaches as far in as cell

 

 

   

 

 

 

 

 

 

 

 

 

membrane
Spore GermTube
(Wpressonum Hyphae
III/IIIIIIIIIIIIII [I’ll/IIIIIIIIIIIIIWIIII—
\\\\\\\\\\\\\\\\ "\H\\\\\\\\\\\\\\\\\\\\\\\
r <( s ‘
\ J
PLANT DEFENSES
Passive

Osolid barriers

0hard surface (potato skin)

0wax and cuticle (very thick on stems or skin of green pepper)
Ochemicals

0phenolic acids (white onions get smudge, purple don't)

0toxic compounds (terpenes, the smell of pines like in Pine-Sol)

Active
Oquick, local cell death - fungus starves because next cell is already dead
also stored poisons leak out protecting by killing fungus

0immune response other cells detect death by chemical messages and
produce other offensive and defensive chemicals
Ochitinase and B-glucanase that breaks down fungal cell walls
Ophytoalexins - are antibiotic and rapidly absorbed by fungi
slignin- a very hard material plant uses to make a new wall
keeping out pathogen, it is usually part of the xylem and other
fibers

PLANT AND PATHOGEN PLAY AN EVER INCREASING GAME OF
WEAPONS

Leads to Defense Response ‘——— Plant Can Recognize Pathogen

\

Pathogen Mutates Plant Mutates

\ /

Plant Can't Detect Pathogen ——_p Disease Returns

What allows a plant to recognize a fungus is probably something on the
hypha surface sort of like an antibody in people.

In plants the protective mutation lasts about 5 years so breeders are always
looking for new resistant plants. If a fungus is not highly sexual the
resistance will last longer.

100

Appendix G

PLANT PATHOLOGY SLTDES

25)BASIDIOMYCETE - bracket fungus, most of the hyphae (or body) is inside
the log

24) LICHEN - a fungal / algal symbiont
23) SLIME MOLD - on shredded bark, plasmodium

7) LATE BLIGHT - dark half of leaf is water soaked and rotting because of
infection, visible fuzziness is hyphae, other half appears to not be infected

8) LATE BLIGHT - on potato tuber, fuzzy parts are spore producing

6) LATE BLIGHT - killed tomatoes

1) RHIZOCTONIA - micrograph of hyphae, note divisions between cells and
branching (possibly spore formation)

21) RHIZOCTONIA - on potato stems, lesions can girdle
2) RUST on cottonwood leaf, note spore pustules
3) CORN SMUT - note black spore producing structures

4) POWDERY MILDEW - on barley leaf, individual hyphae are visible, it is an
obligate parasite

5) SCLEROTINA - it's a plant stem in X-section, the black lumps are sclerotia
or hard-walled resting structures, is a pathogen to several plants

18) VERTICILLIUM causing WILT - vascular tissue blockage due to
breakdown of xylem by enzymes and large number of spores produced, infects
through roots to vascular tissue. Only some vines in this shot are infected.

26) COLLETOTRICHUM - on cucumber leaves, susceptible plant on LEFT,
plant with some resistance on RIGHT, enters through stoma or leaf surface

CLADOSPORIUM - no pictures as it dissolves plant, rots younger tissue so it
will work it's way down stem until it gets to and stops at tissue of a certain age

101

22) BLACK ROT - on Arabidopsis, in early stages, started at leaf tip, caused by
the bacterium Xanthomona

9) PHYTOPHTHORA - on unripe pumpkin, white patches is sporulating
fungus and probably where infection started, light green is rotting and
infected, dark green maybe infected but not producing visible symptoms - yet!

19) PHYTOPHTHORA - micrograph of spores, note thick walls, flat bottom on
left spore where stalk was attached

20) ALTERNARIA - micrograph of spores, note thick walls and multiple
sections, see where stalk was attached

10) PSEUDOMONAS - bacteria on a petri dish
11) CLAVIBACT ER causing RING ROT - a gram stain

12) AN GULAR LEAF SPOT - on cucumber leaf, bacterial disease
(Psuedomonas) mostly follows veins causing necrotic lesions

13) CUCUMBER WILT - on cucumber leaf, bacteria live in and plug xylem,
mainly gets in with the saliva of Cucumber Beetle so infection is carried from
one plant to the next

14) XANTHOMONAS causing BLACK ROT - on cabbage leaf, is devastating to
crucifers, enters through hydathodes (large openings at leaf margins directly
hooked to vascular tissue) as root pressure overnight pushes water out and
produces drops that are part of dew, bacteria naturally on leaf surface move
into drops, as day heats up drops are drawn back in sucking bacteria with it.
Bacteria colonizes xylem moving back progressively from the edge.

15) STREPTOMYCES - some are pathogenic to plants

16) STREPTOMYCES - filamentous growth form and divisions between cells
is visible in this micrograph

17) STREPTOMYCES causing SCAB - on left has caused skin to produce cork
like material

RHIZOCTONIA - on right, in a resting stage that is not a disease to the tuber
but is waiting there to attack next springs vegetation

102

Appendix H

AMERICAN CHESTNUTS AND CHESTNUT BLIGHT
(Castanea dentata and Endothia parasitica)

The American Chestnut ms an important tree. It was very common in
forests of the Eastern US. One out of four trees in the Appalachians was a
chestnut. The nuts were important as a food source - it was a major part of
the diet for squirrels, raccoons and others. Along with oak, chestnut bark was
the major source of tannin for the leather industry. The wood is as rot
resistant as redwood and was used for fenceposts,railroad ties, furniture, etc.
In Italy, a different species of chestnut is often used in place of Wolmanized
lumber. Then there is the empty place in American history and culture:

Under the spreading Chestnut tree,
The village smithy stands - Longfellow

Chestnuts roasting on an open fire
Jack frost nipping at your nose.

This all changed beginning in 1904.
1904-Strange illness noticed on trees at New York Zoological Gardens.

1906-A new fungus then named Chestnut Blight was positively identified as
the cause of the disease

1908-All states in Northeast U.S. report blight is widespread.
1912-B1ight widely reported down to Georgia and out to Iowa and Nebraska.

1913-Blight is found on different species of chestnut in China and Japan but
the trees are not affected at all.

1925-Illinois reports that all of it's chestnuts are dead.
1929-Blight reported in Washington and Oregon.

1938-Blight is found and is damaging chestnuts of yet another variety
(Castanea sativa)in France and Italy.

Considering that the first appearance of blight in the US and Europe was at a
port city and that the fungus doesn't harm the Asian trees probably means
that humans carried the fungus here. In other words, all the damage caused

103

by Chestnut Blight economic, environmental and etc is something we could
have prevented because we didn't know any better. Ahh, the dangers of
technology. Score one more bright move for us.

AND NOW ......... MORE ABOUT THE FUNGUS
-Spores enter the plant through wounds, germinate in summer and grow fast.

-The hyphae lives between cells, sucking food much like a vampire.

-It doesn't directly try to kill the cell but damage occurs as the mycelium grow
so large it crushes and blocks plant tissue, especially the vascular ("veins")
tissue.

-The fungus can also eat on the dead chestnut wood, if it has to.

-Can live in any part of the plant but likes the inner bark best. When it grows
here it forms an ugly, lumpy mass called a canker.

-Since there is vascular tissue in the inner bark the "veins" get blocked.

- If the canker goes all the way around a tree then the tree has been girdled
and the parts above will eventually wilt and die.

-Orange or red spots on the cankers are structures that shoot out spores to be
carried by wind or animals to another tree.

REST ORING THE CHESTNUT TREE-just a dream?
-There has been some work on cross-breeding the smaller Asian chestnut

species with the American but the trees are not as resistant as the Asian
species and don't get very tall.

-In Italy, 1951, it was noticed that some chestnut trees had the Blight but were
not dying or even being hurt too bad - this variety of the fungus was called
hypovirulent (or "less deadly" or hey let's cut to the chase - weaker!)

-There seem to be lots of different types of hypovirulent Blight fungus but
that all of them have a virus - so ..... the disease has a disease!

-If you grow a hypovirulent fungus touching a killer then the virus will be
transferred. So it seems like all you'd have to do is put the hypovirulent
fungus out there and all the killer fungi would get sick and not kill Chestnuts

-BUT the hypovirulence doesn't seem to move to another tree all by itself so
unless we spend BIG$$$ and pay people to find and treat every chestnut tree
this won't bring them back BUT we can do cool things with Chestnut Blight
Fungus in the classroom.

104

Appendix I

TISSUE CULTURE NOTES
-Plant tissue culture is the production from 1 plant of many genetically
identical plants called clones using hormones.
{The traditional method is to take one large plant and divide it into 2 or 3
parts which are then planted in the ground and allowed to grow up for 1 to 3
years.)

It is useful to plant breeders because
-larger numbers (than w/ traditional methods) of plants can be
produced from a single plant
-virus-free plants can be raised,
-the second generation of plants is usually more vigorous
-speeds up crop improvement and plants can be genetically
tailored for certain conditions.

If tissue culture could be done with animals like it is with plants then
we might have a real "Jurassic Park".

3 Stages

Germination

-need young, healthy plant tissue as a source of cells

our source is radish and carrot seedlings in a "sterile" environment
-germinated on disposable petri dish containing germination media (Phase 1)
after seeds have been soaked in sterilizing Silver Nitrate

Stimulating Callus Tissue

-Phase 2 media causes cells to grow into undifferentiated mass (glob) of cells
called callus tissug with plant hormones

-undifferentiated means the cells have a shape not suited or specialized for a
particular job

Stimulating Whole Plant Growth

-after callus has formed, the hormones in the Phase 3 media will cause the
growth of roots and stems and eventually a whole plant

-a HORMONE is a body chemical. In animals they are produced in glands and
travel through the blood to the whole body but only certain body parts (where
they are absorbed into that parts' cells) respond to their message. In plants
they travel through the sap and diffuse into cells. Cells that react to the
hormones message have a specially shaped receptor and when the "LOCK"
meets the "KEY" the cell responds by doing something that involves
chemicals (because we are all basically chemicals).
SOOOOO ...... -they are not directly involved in chemical reactions

-they usually cause a whole series of things to happen

105

Appendix J

TALES FROM THE PET RI DISH FINAL EXAM - WINTER SEMESTER '96'

NAME

 

1) In microbiology, the purpose of sterile technique is:
2) List 3 ways to sterilize using heat:
1.
2.
3.
3) List 2 common liquids used for sterilizing (including the percentage of the liquid usually most
effective):
1 .
2.

4) "Invert", means to:

5) Why would a petri dish be "inverted"?

6) Describe the proper way to remove a petri dish lid to work on it:
1.

2.

7) List the 4 steps in transferring a bacteria or other culture from one petri dish to another:
1.

2.
3.
4.

8) List and briefly discuss 2 ways not mentioned above, to reduce exposure of a person or culture.
I don't have a specific answer in mind. Use common sense.

1.

2.
9) Define the word "media" as used in microbiology

 

106

10)Define MICROBIOLOGY in your own words. Also, list as many jobs as you can think of that
use microbiology knowledge or skills. You can use the back of the page.

11) An enzyme: (CIRCLE ALL THAT APPLY)
(a) is used up in the processes they are part of
(b) is directly involved in chemical reactions
(c) usually stimulates cells into doing something with chemicals.
(d) is a nutrient or source of food
(e) is not used up in the processes they are part of
(f) can cause more than 1 action to happen

(g) is not a nutrient or source of food
(h) will cause 1 and only 1 action to happen.

12) T or F An enzyme is a type of carbohydrate.

13) T or F Enzymes were originally found in living things

14) T or F Enzymes can work inside and outside of organisms

15)The speed that an enzyme works at depends on: (CIRCLE ALL THAT APPLY)
(a) concentration of the enzyme

(b) amount of available light
(c) presence of inhibitor(s)

((0 pH

(e) radiation

(f) temperature

(3) amount of available protein

16) The names of enzymes usually end in

 

17) The names of sugars usually end in

18) The weight of bacteria living in the average human body is about equal to
(a) a gram
(b) nothing, none live in our bodies
(c) seven pounds
(d) the weight of a 12 ounce can of pop.

19) DISCUSS this statement. "Bacteria only live in special locations."

 

 

20) The first forms of life on Earth appeared about 3 billion years ago & were probably
a) bacteria b) fungi c) viruses (1) plants

21) Bacteria and fungi do not have mouths, how does their food get in?

107

22) Complete this chart about the differences and similarities between viruses, bacteria and
fungi. Words in parentheses ( ) are choices to use as answers, but those in brackets [ ] are only
for explanation.

FUNGI VIRUSES BACTERIA

 

"cell" organization
(single, colony,
multicellular)

 

method of getting food
[or new "cell" material]

 

internal membranes
(yes or no)

 

exterior mat'l (chitin,
protein, protein/ lipid)
rank in size (smallest,
medium, largest)

 

 

what gas is required to
live (oxygen, other,
and none)

 

style of reproduction
(sexual,asexual,
neither)

 

alive or not
(yes or no)

 

 

 

23) About 5,000 to 10,000 species of bacteria have been discovered and named. This is
only about percent of all the species of bacteria that probably exist.

24) Most scientists who study them agree that it easier and more useful to identify bacteria by
their abilities than by their appearance. TRUE FALSE

25) Yeast is an example of what type of organism?
26) The 3 shapes of single bacteria cells are: (Draw a small, simple picture of the shape

also.)
a.

108

27) Single bacterial cells group together in what three ways:
a. b.

c.
28) Of the 6 following words there are 2 groups of 3 that make sense together. Put them in the
right groups on the lines below.

aerobic, anaerobic, with oxygen, without oxygen, respiration, fermentation

Group 1

 

Group 2

 

29) How many bacteria does it take to start a colony of bacteria on a petri dish media ?

30) The purpose of selective media is to find what concentration of something (pH, salt, etc) a
bacteria (or other micro-organism) likes best. TRUE FALSE

31) The purpose of a serial dilution is: (best answer only)

(a) to keep unwanted organisms from growing
(b) to find what concentration of something that bacteria like best
(c) to find the best concentration of something depending on the purpose of the dilution

32) In a serial dilution if the concentration of the first container is 10:10 and the concentration of
the second container is 9:10,, then list the concentrations of the next 4 containers (extra credit
-list % of desired substance in the solution).

CONTAINER 1 fit 2 3 4 5 6

 

CONCENTRATION 10:10§r9:10

 

PERCENTAGE

 

 

 

 

 

 

33) Give one example of something serial dilution might be used to find out.

 

34) The purpose of both fermentation and respiration for micro-organisms is

 

35) TRUE or FALSE Most foods produced using microbes involve fermentation.

36)TRUE or FALSE Most beverages produced using microbes involve fermentation.

37) TRUE or FALSE Fermentation always results in the production of alcohol.

38) When a micro—organism is used to produce a food or beverage,

it "eats" using and then

makes

 

109

39) Lactobacilli use to digest and are used

by the food industry to make and

 

40) All production of beer and wine depends on what microbe?

 

41) Name some of the most commonly desired by-products of microbial activity

1 2 3

42) Choose one of the phrases below. Describe which micro-organisms are doing what with
what and how that results in the desired product.

a) Hops, Malted Barley 6t Water into Beer
b) Granulated Sugar, Lemon, Ginger, Tartar into Ginger Ale

43)Define the following terms-

plant pathology

pathogen.

hypovirulent

virulent

44) List the three major groups of organisms that cause plant diseases in order from most

diseases to least diseases.

45) {Explain why] When we cultured Chestnut Blight fungus from bark we
a) soaked the bark in bleach
b) but for only 5 minutes.

46) If Potato Rot fungus was around in a potato field and the weather was hot and dry, would a
large number of the potatoes probably get the disease? Explain your answer.

47) What one development in microbiology has significantly increased the human lifespan
since World War II?

110

48) Explain what is happening in the diagram shown below.

1.

5' Germ Tube

Spore .
E l Appressonum
/

2 _

 

 

 

 

 

 

\ J J

 

49) We will culture Chestnut Blight from bark and grow it on a PDA dish with a different type
of Blight. Predict what you think will happen.

50) Talk about the questions below.
a) Why was the American Chestnut an important tree?

b) What happened to it? (when, how long, from where, how many)

c)Why is the chestnuts' decline important for ourselves and society to think about?

111

51) There are 3 conditions for a plant to get a disease. The third condition is that the plant is
susceptible.
(a)What does susceptible mean

(b) Why is it worth mentioning especially when we are discussing plant diseases?

52) What is the difference between passive and active plant defenses?

What sort of defenses to disease do plants have?List and explain some.

53) We will infect a cucumber plant with a weak plant disease, then a few days later with a
second stronger disease. Describe what will happen to the plants resistance.

54) A plants ability to resist a pathogen lasts for only a few years and vice-versa. Explain why
this might be.

55) List as many things as you can think of that would happen in a Medical Technology Lab
like one found in a hospital.

112

Appendix K

STUDENT PRE-CLASS INTERVIEW

1) What Is Your:
Name

Age

Sex

Born Where,
Living Where

2) What is name of this class?

3) What have you heard about the class before this moment?
4) Why did you choose to take this class?

5) What do you expect to do in the class?

6) Do you expect to be excited by or (dis-, just plain, or especially) interested in
the following parts of the class?

Experiments

Field Trips

Information

7a) This is a class about microbiology, does that tell you something new or
different about it?

7b) What is microbiology or is usually considered to be part of it?
8) What is a microbe?

List types

List characteristics
9) Who uses microbiology and how.

In General

In making or studying foods
In studying plant diseases

10) What ideas do you expect to learn from this class?

11) What skills do you expect to learn from this class?

113

12) Do you think there are any skills or information from this class that you
will be able to use in:

the real world,

a future job

a later science class
13) Do you think it is valuable to simply have general knowledge (such as

how cheese is made) that you may not use in the real world, a future job or a
later science class?

14) Have you considered a career in science or a related field?

15) How do you feel about science classes in general (interested, intimidated,
had 1 good past teacher, etc)?

114

STUDENT POST-CLASS INTERVIEW
1) What Is Your:
Name
Age
Sex
Born Where,
Living Where
2) What is name of this class?

3) Was the class what you expected it to be?

4) Are you glad that you chose this class or do you wish you had taken
another?

5) List 3-5 things you did in this class.

6) Were you excited and/ or (dis-, just plain, or especially) interested in the
following parts of the class?

Experiments

Field Trips

Information

7) What is microbiology or is usually considered to be part of it?

8) What is a microbe?
List types

List characteristics

9) Who uses microbiology and how.
In General
In making or studying foods

In studying plant diseases

115

10) What ideas did you learn from this class and/ or How has taking this class
changed your view of the world?

11)Name 3-5 skills you have learned from this class.

12) Did you learn any skills or information from this class that you will be
able to use in:
the real world,

a future job
a later science class
13) Do you think it is valuable to simply have general knowledge (such as

how cheese is made) that you may not use in the real world, a future job or a
later science class?

14) Now that you have taken this class would you consider a career in science
or a related field?

15) In the pre-interview you said about science classes in general, has
this class changed your feelings about that or how do you feel about this class
compared to others you've taken?

116

Appendix L

FIELD TRIP TO WIN ERY REPORT FORM

1) WHAT IS THE PURPOSE OF THIS FIELD TRIP?

2) WHAT ARE SOME NUMBERS THAT DESCRIBE THEIR BUSINESS?

3) COMPARE THE IMPORTANCE OF ST ERILE CONDITIONS AT
CAMPBELLS AGAINST THE WINERY.

4) WHAT WAS THE BEST PART OF THE TRIP? WHAT WAS THE WORST
PART OF THE TRIP (not including the bus ride)?

5) WHAT CARBONATED BEVERAGES DO THEY PRODUCE AT THE
WINERY?

6) DIAGRAM THE PROCESS OF PRODUCING WINE AT ST. JULIAN (Use
back of paper).

117

Appendix M

TISSUE CULTURE EXPERIMENT

Plant tissue culture is production of many identical plants or clones from 1
plant. It is useful to plant breeders because virus-free plants can be raised,
speeds up crop improvement and plants can be genetically tailored for certain
conditions. If tissue culture could be done with animals like it is with plants
then we might have a real "Jurassic Park".

Seedling pieces will be placed on one of four different medias. The
media are Murashige and Skoog A, B, C and Control. The A, B and C media
vary in their proportion of the hormones kinetin and indole acetic acid. The
Control media contains neither hormone.

3 Stages

Germination

-need young, healthy plant tissue as a source of cells

our source is radish seedlings in a "sterile" environment

-germinated in autoclaved petri dish and paper towels, moistened with
autoclaved bleach solution (3:1, water:bleach)

Stimulating Callus Tissue

-cause cells to grow into undifferentiated mass (glob) of cells called callus
tissue with plant hormones

-cut sections of stem are placed on media containing kinetin &/ or 1AA, the
stems absorb the hormones from the media

-undifferentiated means the cells have a shape not suited or specialized for a
particular job

-see your Tissue Culture Notes to be refreshed as to what a hormone is

Stimulating Whole Plant Growth
-after callus has formed the hormones will cause the growth of roots and
stems and eventually a whole plant

MATERIALS

Alcohol Wax Pencil

5% Bleach Solution Radish Seedlings

Tweezers Sterile Petri Dishes, 250ml Beakers
Alcohol Burner Autoclave (pressure cooker) and Oven

Enclosed Work Area Murashige 8r Skoog tissue culture media- A,B,C &
Control

118

PROCEDURE

Wash hands with soap and water.

Sterilize work surface

Media Preparation

1) In 2x container add 90% of final volume water

2) While stirring, add powdered media.

3) Rinse media container into 2x container with small volume of water.
4) Add agar.

5) While stirring adjust to pH 5.7 + or - 0.1.

5) Bring to final liquid volume.

6) Heat solution to 100°C while stirring.

7) Autoclave media. Label plates appropriately - Control, Media A, etc.
8) Pour plates. Allow to solidify at room temperature

Placing Seedlings On Media
-Inside Enclosed Work Area(glass aquariums):

-Set up work area: sterilize glass inner surfaces with bleach, the empty sterile
petri dish bottom will be where you cut up seedlings, the top will serve as the
cover for the 250ml beaker. The alcohol lamp will be burning outside.
-Top layers of moist paper towel can be removed from seed dishes.
-Remove 1 germinated seedling from dish with sterile tweezers, re-cover
dish.
-Inside a second sterile dish and with a sterile razor blade cut off all root and
shoot tissue. Cut remaining stem into sections between 1/ 2 and 1 cm. long.
-Flame razor in-between each seedling.
-With sterile forceps put stem sections into sterile beaker, cover with other
half of sterile dish.
-After all seedlings are cut up, add 70% alcohol, cover and shake gently for
exactly 1 minute.
-Pour off alcohol (using lid to keep stems from falling out) then add enough
10% bleach solution to cover, put lid on and shake gently for 5 minutes.
-Pour off bleach, then rinse stems 3 times with sterile distilled water.
-With sterile forceps put stem sections onto media. 4 sections of stem can be
evenly spaced around the petri dish.
-Tape dish closed and put it in clear plastic bag.
-Leave bags in location with appropriate light and temperature.

Temp 74-80°F constant, especially during regeneration stage.

Light from window is adequate, incubator is preferred.

Keep cultures in clear plastic bag (to reduce airflow).

Follow-up
-Remove contaminated cultures to another bag when discovered.

-Cell division should begin to produce a callus shortly (1 week ?). It should be
at an ideal size of about 1 cm. diameter in 1 month or so. Shoots and roots
should begin to appear shortly.

119

Appendix N

BREWING BEER

Fermentation is an important chemical process for the baking and
brewing industry. Beer is made as the result of a fermentation and involves
four important ingredients.

Fermentable sugars (usually malted barley)
Hops

Water

Yeast

1) Malted barley is produced naturally by putting barley seeds into water
where they germinate. This means enzymes are breaking down stored
starches into sugars, a process called mashing. After the process is done and
the seeds are dried they are now said to be malted. It is these sugars that the
yeast will ferment into alcohol, carbon dioxide and the flavor of beer.
Sometimes breweries replace some of the malted barley with malted corn,
rice, wheat, rye, or another grain.

There are two kinds of enzymes doing different but important jobs in
mashing. Proteases are breaking down proteins into amino acids. The yeast
uses these to build/ grow more yeast cells. This process helps to improve the
clarity and foam potential of beer. Alpha-amylase and beta-amylase break
down the starch which is a bunch of very long chains of glucose molecules.
Alpha-amylase cuts the long chains in the middle, repeatedly, until the
chains are quite a bit shorter. At the same time the beta-amylase works by
"nibbling" at the ends (an enzyme can't really nibble because it's not alive).
Beta-amylase cuts off chains that are one, two or three glucose molecules
long. At this size they are fermentable sugars.

2) Hops are green cone-shaped flowers that grow on vines and have been
used in brewing for thousands of years. Hops give a bit of bitterness to beer

that balances the sweetness of the malt. They also retard spoilage and add to
the head of the beer.

3) Beer is 90% water. The water provides the proper environment for
yeast to ferment the sugars of the malted barley.

4) Yeasts are a type of fungi and are living microbes. Thousands of
different kinds can be found. Most of the yeasts used in brewing are called
BREWER'S YEAST (Usually Saccharomyces cerevisiae for ale and

Saccharomyces carlsbergensis for lager). Most brewers guard the identity of

120

the specific species of yeast that they use. Baker's yeast is used for making
bread.

CLEANING BOTTLES

1) Wash bottles out in hot water and detergent.

2) Rinse out soap

3) Sterilize by immersing in 10% bleach solution for 5 - 10 minutes.

4) Rinse with clear water until bleach odor has disappeared.
5) Drain the bottles dry.

PREPARING FERMENTATION LOCK

As the yeast ferment the sugar they will produce a large quantity of carbon
dioxide gas. At the same time we want to prevent contamination by air-borne
microbes and keep oxygen from entering the bottles. Both needs can be met
with one piece of equipment. Invert a gallon jar of water in a pan of water.
The jar should be secured so that when it is full of gas it does not tip and the
jar should also have a spacer underneath so that the hoses from the bottles
are not crimped. Also, be ready to manage the water level as the yeast will
produce more than enough gas to empty the gallon jar.

BREWING INSTRUCTIONS

1) However many bottles are being brewed determine the size of the master
mix. Mix 55 grams of malt extract and 0.28 g. of hops in 350 ml of tap water
for each bottle of beer. Put all of this in one large pot.

2) Bring to a boil and boil for 5 min.

3) Strain the mixture from step 2 (it's called WORT) through cheesecloth into
a 1L flask and cool to 70 degrees F

4) Find the beginning alcohol content by pouring a small amount into the
hydrometer vessel, then slowly lower the hydrometer into the liquid (don't

spill). Record the specific gravity shown on the hydrometer
then pour this sample down the drain.

5) Pipet 7 ml of JOEY D'S YEAST SOLUTION into a clean cappable bottle. Add
enough wort to bring the liquid up to just past the shoulder of the bottle.

6) While the bottles are being filled, take a drop of the mixture from the
beaker and make a wet mount slide. Count the yeast cells on the slide using
medium power in each of the 4 corner areas and the center and the find the
average. This is the initial population at TIME 0. Each day for the next
several we will CAREFULLY open one or two of the classes bottles and make
the same type of count. Record this information each day below.

121

7) Insert a one-hole stopper with a length of tubing attached and insert the
tubing under the inverted jar to form a fermentation lock to allow
fermentation to begin at room temperature.

8) After vigorous bubbling subsides (1 - 2 days) remove the fermentation lock
and cap the bottle.

9) Allow beer to mature at room temperature for another 2 - 5 days.

10) Take a second hydrometer reading here . Do the math
with this result and your first reading as shown in question #1

1)Beginning Specific
Gravity _____
Final Specific Gravity _____
X 105 = _ % alcohol by weight
Alcoholic Proof __ % alcohol by weight X 2 = ___Proof

Extra credit: Do the same math but for some other day or days before the final
day and do it on a separate sheet of paper.

2) Why are water, malt extract and hops boiled in step 1 before adding yeast?

3) Why take a hydrometer reading before adding yeast and after fermenting?

4) What is the purpose of the fermentation lock and how does it work?

Yeast population Data Analysis
1) Graph the average yeast population versus time.

2) Explain the shape of this curve.

122

Appendix 0

CHESTNUT BLIGHT

Isolating The Fungus, Transmitting Hypovirulence,
Testing For Transmission

Background

The word virulent (V) means that a disease causing agent is strong or as in
the case of Chestnut Blight, that the fungus can kill a tree. Hypovirulent (H)
means the disease agent is weaker and would probably not kill a tree though
the tree may look messed up. On PDA it is often possible to visually tell if a
mycelium is H or V. A V fungus will have pretty much smooth and round
edges and there will be concentric rings of various colors. The edges of an H
fungus will be deeply lobed and the colors won't be as neatly separated.

Materials

Plates of PDA agar

40% Bleach Solution

Small containers to soak bark
Sterile Water

Sterile Paper Towel

ISOLATING THE FUNGUS
1) Collect bark from an American Chestnut in the area immediately around a
canker.

2) Put a piece of bark in 20% bleach solution for ~5 min. Make all further
transfers using sterile technique.

3) Rinse bark twice by soaking in new sterile water for 1 min. each time.
4) Dab dry with a paper towel.

5) Transfer bark to PDA plates and label appropriately. More than 1 piece of
bark may be on a plate though the colonies may grow overlapping.

6) Incubate at room temp. for 5 or more days, observing the plates daily.
When mycelia develops, decide by appearance if fungus is H or V.

TESTING FOR HYPOVIRULENCE
1)Remove a 1/ 4" to 1/ 2" deep plug (about the size of 1 to pencil erasers) from
a Golden Delicious apple.

123

2) Put a chunk of whichever fungal cultures are being tested into the hole.
Pack in so that all the inside of the hole is touching fungus. Replace some of
the apple and scotch tape the hole closed to reduce contamination.

3) Allow 14 or 21 days for decay, then inspect and decide by the size of decayed
areas as shown on the diagrams below, if the fungus is H or V.

   

V2 H5
60-80mm ~30mm
EDGE OF ROTTEN AREA
Chestnut Blight Fungus Other Fungi
-a soft brown color -light or yellow brown
-firm edge that's very circular -irregular, squishy
-apple meat would core out -wouldn't core out

like a melon ball

TRANSMITTING HYPOVIRULENCE
1) Transfer a small section of the newly isolated fungal colonies to a new PDA
plate.

2a) If suspected to be V, also add a small piece of the fungus E17f.

2b) If suspected to be H, also add a small section of the fungus Magnificent 7.
The transferred pieces should be an inch or two apart and towards one side.
That way as the mycelia grows you will be able to observe that it has the
expected appearance at the beginning and there will also be room for the
anastomosed mycelia to clearly show an altered appearance. Incubate at room
temperature for 5 more days. Observe each day.

3) If the hypovigglange was tranaferrgd then at the point where the two

mycelia meet there should begin to be a change in the appearance of the V
fungus, looking more like an H type.

NOTE: 3 rules for determining if a fungus is truly H it must:
-be less virulent than normal
- be able to be transfer it's hypovirulence by hyphal anastomosis
-be caused by cytoplasmic factors such as virus

124

Appendix P

ACQUIRED SYSTEMIC RESISTANCE IN CUCUMBERS

Objective: Demonstrate that some plants can be induced by non-lethal attack
of one pathogen to resist a second attack by a second, different pathogen.

Materials:

Pathogen Cultures - Colletotrichum lagenarium (Anthracnose Fungus)
produces necrotic lesions on leaves
- Cladosporium cuc4umerim (Scab Fungus)
kills entire plant

Cucumber Varieties - SMR 58 - genetically resistant to Scab Fungus,

susceptible to Anthracnose Fungus

- National Pickling - susceptible to both Fungi

Distilled water

Glass "hockey stick" or stirring rod

Pipette

Small flask or beaker

Procedure:
1) Germinate then plant cucumber seeds 2-3 weeks prior to use. Should have
2 sets of true leaves at time of first inoculation.

2) Culture pathogens for 7-10 days prior on PDA (Potato Dextrose Agar) or on
V-8 agar.

3) When spores have developed, add a few mls. of distilled water. Rub
vigorously with glass rod but don't tear media. After a good rub, pour the
liquid (this is the spore suspension) into clean container.

4) Put 0.1ml drop of spore suspension on slide, put on a cover slip and count

spores. The desired amount is around 5 X 105 spores/ ml and there are 1000
fields across a cover slip, so under medium power in 5 fields (top, bottom, left
side, right side, center) you should see an average of about 500 spores/ field.

5) TO INDUCE RESISTANCE

Depending upon which of the comparisons (shown below) you are
investigating, inoculate the first true set of leaves on each plant with a 5-10
microliter droplet (30 droplets/ leaf) of the appropriate spore suspension.
Incubate in a humidity chamber (can be a plastic bag or box, anything where
the humidity can be maintained at 100%) for 24 hours.

125

THE COMPARISONS
A) To see if the inoculation with the first fungus actually does increase
resistance to a second fungus.
First Inoculation Second Inoculation
Distilled Water Only VS. Spore Suspension

B) To see how much protection an inoculation provides from a 2d
inoculation with the same fungus.
Scab VS. Scab and Anthracnose VS. Anthracnose

C) To see if the first fungus must be a weaker species to provide resistance to a
stronger one.
Scab - first, Anthracnose - 2d VS. Anthracnose - first, Scab - 2d

6) CHALLENGE INOCULATION: Open incubation chamber and allow to
equilibrate with environment. Inoculate second set of true leaves as
described above with the second spore suspension at the same concentration.
Asses over 2-4 days the condition of the challenged leaves and the plant as a
whole.

TASKS
1 Figure out how many cucumber seedlings should receive each type of the
first inoculation?

2 Of these, which ones should be in the same humidity chambers?

3 Figure out how many cucumber seedlings should receive each type of the
second inoculation?

4 How can we measure the difference in resistance?

5 Look at the comparisons. Predict outcomes for the three experiments and
say what you would see or measure when looking at the plants.

126

Appendix Q

PD3, 4 and 5 Student Pre-Test and Post-Test Results

 

 

Pre-Test Post-Test
Student Number Correct Percentage Number Correct Percentage
Number

1 26/ 100 26 77.5/ 100 77.5
2 19/ 100 19 80/100 80
3 33/ 100 33 95/ 100 95
4 26/ 100 26 42/ 100 42
5 27/ 100 27 83/ 100 83
6 345/1% 32 755/110 68

52/104 50 75/104 72
7 27.5/ 1% 26 70/ 110 63
8 285/ 1% 31 78/ 110 70
9 22.5/ 1% 21 72/ 110 65
10 28/ 1% 26 84/ 110 76
11 21/ 1% 20 60/ 110 54

49/104 47 68/104 65
12 26.5/ 1% 25 36/ 110 32
13 51/ 1% 48 106.5/ 110 96
14 27/ 1% 25 76/ 110 69
15 33.5/104 32 97/ 104 93
16 23/104 22 67.5/ 104 65
17 34/104 33 87/ 104 84
18 25/104 24 805/104 77
19 205/104 18 535/104 51
20 17/104 16 32/104 30
21 26/104 25 77/104 74

24

26

27

19.5/104
26/104
28/104
27/104
22/104

15/104

19

27

26

21

14

127

59/104
60/104
575/104
56/104
455/104

805/104

56

58

55

43

128

Appendix R

PD3, 4 and 5 Student Demographic Data - Age and GradePoint

 

 

Student Date Of Age At Start Prior gifto During
Number Birth Of Class to BAHS PD class PD class

1 3—1-79 15 1.80(8th) 3.30 2.67
2 9-1-78 16 NA 1.63 1.87
3 11-16-76 17 2.40 3.00 3.17
4 1-3-79 15 0.00(7th) 1.75 1.00
5 10-10-79 15 2.57 2.45 3.32
6 2-8-78 16 0.80(7th) 3.30 3.42

17 2.90 2.08
7 4-27-76 18 1.00 2.45 3.10
8 8-29-76 18 2.72 ---- 3.25
9 4-8-77 17 1.80 3.83 2.67
10 1-19-77 18 1.50 3.15 3.50
11 8-26-78 16 2.50 3.67 3.00

17 ---- 3.42 3.30
12 7-20-77 17 2.70 2.80 1.13
13 7-28-65 29 N A 3.80 3.58
14 2-12-78 16 0.00(8th) 3.10 2.36
15 10-25-80 15 1.11(7th) 3.00 3.67
16 6-20-78 17 1.80 3.17 2.00
17 2-25-80 15 1.1(8th) 2.90 3.30
18 1-27-78 17 1.71(Acad) 2.40 2.08

3.00(VoTech)

19 1-4-80 16 1.3 2.00 2.18

20 4-3-78 17 0.60 2.30 0.50

Student
Number

1

2

10

11

12
13
14
15
16
17

18

19

20

Date Of
Birth

3-1-79
9-1-78
11-16-76
1-3-79
10—10-79

2-8-78

4-27-76
8-29-76
4-8-77

1-19-77

8-26-78

7-20-77
7-28-65
2-12-78
10-25-80
6-20-78
2-25-80

1-27-78

1-4-80

4-3-78

128

Appendix R

Age At Start

Of Class
15
16
17
15
15

16
17

18

18

17

18

16
17

17
29
16
15
17
15

17

16

17

PD3, 4 and 5 Student Demographic Data - Age and GradePoint

 

GPA.

Prior Prior to During
to BAHS PD class PD class
1.80(8th) 3.30 2.67
NA 1.63 1.87
2.40 3.00 3.17
0.00(7th) 1.75 1.00
2.57 2.45 3.32
0.80(7th) 330 3.42

2.90 2.08
1.00 2.45 3.10
2.72 ---- 3.25
1.80 3.83 2.67
1.50 3.15 3.50
2.50 3.67 3.00
---- 3.42 3.30
2.70 2.80 1.13
N A 3.80 3.58
0.00(8th) 3.10 2.36
1.11(7th) 3.00 3.67
1.80 3.17 2.00
1.1(8th) 2.90 3.30
1.71(Acad) 2.40 2.08
3.00(VoTech)
1.3 2.00 2.18
0.60 2.30 0.50

‘04

Student
Number

10

11

12
13
14
15
16
17

18

19

20

Date Of
Birth

3-1-79
9-1-78
11-16-76
1-3-79
10-10-79

2-8-78

4-27-76
8-29-76
4-8-77

1-19-77

8-26-78

7-20-77
7-28-65
2-12-78
10-25-80
6-20-78
2-25-80

1-27-78

1-4-80

4-3-78

128

Appendix R

Age At Start

Of Class

15

16

17

15

15

16
17

18

18

17

18

16
17

17

29

16

15

17

15

17

16

17

PD3, 4 and 5 Student Demographic Data - Age and GradePoint

 

GPA.

Prior Prior to During
to BAHS PD class PD class
1.80(8th) 3.30 2.67
NA 1.63 1.87
2.40 3.00 3.17
0.00(7th) 1.75 1.00
2.57 2.45 3.32
0.80(7th) 3.30 3.42

2.90 2.08
1.00 2.45 3.10
2.72 ---- 3.25
1.80 3.83 2.67
1.50 3.15 3.50
2.50 3.67 3.00
---- 3.42 3.30
2.70 2.80 1.13
N A 3.80 3.58
0.00(8th) 3.10 2.36
1.11(7th) 3.00 3.67
1.80 3.17 2.00
1.1(8th) 2.90 3.30
1.71(Acad) 2.40 2.08
3.00(VoTech)
1.3 2.00 2.18
0.60 2.30 0.50

 

129

21 5-2-79 16 0.8(8th) 3.20 3.08
2 1-14-79 17 2.80 ---- 2.40
23 3-12-79 16 0.67 3.50 3.50
24 12-8-77 18 2.00 2.83 1.25
25 9-4-78 17 0.50(Acad) 1.20 2.50
2.90(VOTech)
26 3-4-75 20 NA 2.18 3.00
27 1-10-76 20 2.0 3.40 2.75

Students 1 - 5 were in PD3, students 6 - 14 were in PD4 and students 15 - 27 were in PD5. Students
#6 and 11 were in both PD4 and PD5.

Items in ( ): (7th) or (8th) indicate student did not previously attend high school. Some of the
students with parentheses are older than their class but were retained in one of the upper
grades.

Students 18 and 25 attended the Van Buren Vocational And Technical Training Center prior to
BAHS. The (Acad) refers to the students GPA at their home school.

Student
Number

10

11

12
13
14
15
16
17
18
19
20

21

130

Appendix S

PD3, 4 and 5 Student Demographic Data - Attendance

Block Periods
Of Class
Pres./Abs.-%
34/44-77
44/44-100
32/44 - 73
33/44 - 75
42/44-95

32/39- 82
69/81 - 85

35/39-90
30/39-77
28/39-72
29/39-74

38/39-97
80/81 -99

19/39-48
29/39-74
38/39-97
76/81 -94
67/81-83
69/81-85
63/81 -78
54/81 -67
51/81 ~63

65/81-80

Percentage

Of Days
For Year

Unavail.
Unavail.
Unavail.
Unavail.
Unavail.

Unavail.

85

Unavail.
Unavail.
Unavail.
Unavail.

Unavail.

90

Unavail.
Unavail.

Unavail.

93
87
88
62
71

63

BAHS Entry

Date

8-25-93
12-1-93
3-15-94
8-24-93

2-22-94

12-7-93
8-26-92
8-24-93
8-28-95
1 1 -6-95
8-29-94
3-15-94
8-24-95
8-18-94

10-5-94

Grade
On Entry

9
9

10

10
11
11

10

10

11

11

10

Student
Number

10

11

12
13
14
15
16
17
18
19
20

21

130

Appendix S

PD3, 4 and 5 Student Demographic Data - Attendance

Block Periods

Of Class

Pres./ Abs. - %

34/44-77

44/44-100

32/44-73
33/44-75
42/44-95

32/ 39 - 82
69/ 81 - 85

35/39-90
30/39-77
28/39-72
29/39-74

38/39-97
80/81 ~99

19/39-48
29/39-74
38/39-97
76/81-94
67/81-83
69/81 - 85
63/81-78
54/81 -67
51/81-63

65/81-80

Percentage

Of Days
For Year

Unavail.
Unavail.
Unavail.
Unavail.
Unavail.

Unavail.
85

Unavail.
Unavail.
Unavail.
Unavail.

Unavail.
90

Unavail.
Unavail.
Unavail.
93
87
88
62
71

63

BAHS Entry

Date

8-25-93
12-1-93
3-15-94
8-24-93

2-22-94

3-15-94
8-24-95
8-18-94

10-5-94

Grade
On Entry

9
9

10

10
11
11

10

10

11

11

10

p

24

26

27

57/81 -70
75/81 - 93
63/81 - 78
56/75-69
46/81 -57

51/81-63

87

72

78

72

131

1-22-96

9-5-95

1-19-95

1-29-96

1—22-96

8-25-95

11

10

11

12

11

Student
Number

10

11

12

132

Appendix T

PD3, 4 and 5 Student Demographic Data - Grade Level

MEAP

Low
Low
10-94

Low
Low
1094

Moderate
Moderate
10-94

Low
Low
10-94

Low
Low
10-94

Low ->Moderate

Moderate
10-93 3-94

No Information Available

Moderate
Low
3-94

Moderate
Moderate
3-94

Low
Low
10-94

Moderate
Moderate
10-93

CAT Brigance

6.8
6.9 ---------
3-94

7.4
5.1 ---------
3-94

10.7
10.3 ---------
3-94

2.3
3.3 ---------
394

7.9(8th)
5.9 ---------
3-93

12+
8.5 ---------
3-94

9.3
5.6 ---------
3/94

11.6
9.6 ---------
394

9.4
12+ ---------
10-92

9.6
9.3 ---------
3-94

9.4
12+ ---------
3-94

Iowa

13

14

15

16

17

18

19

20

21

24

133

Moderate

Satisfactory ......
10-93

Moderate 89
Moderate 6,]
10-94 3-94
low 11.2
Satisfactory 12.9
10-94 3-95

Satisfactory (7th)
Satisfactory (7th) .........

10-92

low 9.6
Moderate 11,0
3-95 3-94

Satisfactory (7th)
Satisfactory (7th) ......
10-92

Moderate (7th)
Satisfactory (7th) ......
10-90

No Information Available

Moderate 7,9
Low -> Moderate 8.3
10-94 10-95 4-94

Moderate (7th)
Moderate (7th) ......

10-92

Low 6
Low 8
10-95 4-94
Low

N A ......

10-94

---~~----

(T ABE
12+
12+
8-92)

13.5

13.5

4-95

134

26 Low
Low ---------------------
3-96

27 Satisfactory ...............
Moderate ......
10-95

All grade levels are listed with reading on top and math in the middle. The date that the test
was administered is on the bottom.

MEAP math test results are described on the range Low-Moderate-Satisfactory

MEAP = Michigan Educational Assessment Program
CAT = California Achievement Test
Brigance = Brigance Inventory of Basic Skills

Iowa: Iowa Survey Of Basic Skills
TABE = Adult Basic Education

nICHIGnN STATE UNIV. LIBRARIES
IIIWIN"II"IlllllllllWWIIWHIIHIIIIII
31293015592508