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EVALUATION OF A STREAM STUDY UNIT
USED AS AN INTRODUCTION TO HIGH SCHOOL BIOLOGY
BY

Sandra R. Kransl

A THESIS

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

MASTER OF SCIENCE

Department of Natural Science

1991

633 - 333’ ’2

ABSTRACT

EVALUATION OF A STREAM STUDY UNIT
USED AS AN INTRODUCTION TO HIGH SCHOOL BIOLOGY

By

Sandra R. Kransi

The stream study unit was used as an introduction to a
first year biology course required of high school
sophomores. The unit set out to help students understand
the underlying principles of environmental biology, to
increase student achievement in later units, and to increase

positive student attitudes toward science.

The students’ understanding of ecological principles
and their attitudes toward science were measured using pre-
and post-tests and pre- and post- attitude surveys. The
results indicated significant student achievement and

positive attitude changes as a result of the implementation

of the unit.

Student test scores on later units in respiration and
in photosynthesis were compared over a five year period.
The scores from the latter two years of that period (during
which the ecology unit was used as an introduction) were

significantly higher than those from the prior three years.

W

Sincere appreciation must be expressed for the
assistance, support and encouragement provided by Dr. Howard
Hagerman, Dr. Martin Hetherington, and Dr. Clarence Suelter
of Michigan State University. Without their tireless
efforts on behalf of the teacher workshops in molecular
biology and in environmental/behavioral biology, this thesis

would not have been possible.

Gratitude also goes to my father whose “You Can Do
Anything“ attitude has been responsible for much success in
his children’s lives and to my mother who provided the most
important model of what an excellent teacher must be. Most
of all I am grateful to my husband, Harold. for his love,

his patience and his support of all I do.

TABLE OF CONTENTS

ACKNOWLEDGEMENTS
LIST OF TABLES

CHAPTER 1. INTRODUCTION .

CHAPTER 2. INSTRUCTION

Overview .

Outline of Unit .
Analysis of Laboratories .
Analysis of Field Techniques
Analysis of Simulations
Analysis of Films

CHAPTER 3. EVALUATION
Pre-Tests and Post-Tests .
Comparison to Past Years .
Attitude Surveys
Exit Interviews
Teacher Observations

CHAPTER 4. CONCLUSIONS
Learning of Ecological Concepts
Learning of Respiration/Photosynthesis
Attitudinal Change
Future Plans

WORKS CITED.

SELECTED BIBLIOGRAPHY

iv

10

10
12
14
24
28
3O

36

36
37
39
41
46

4s
48
49
51
56
58

59

APPENDIX A--STUDENT HANDOUTS

Limiting Factors Handout .
Food Web Assignment Handout

APPENDIX B--STUDENT LABORATORIES

Limiting Factors for Algae .

Temperature As A Factor In Determining
Dissolved Oxygen , .

pH of Common Substances

Organisms and pH .

water Ouality--Testing for Ions

Introduction to Microscopes

Analysis of Feeding Groups of
Stream Macrolnvertebrates

Crayfish

Crayfish/insect Comparison

Observation of Algae and Protozoans

Schooling Behavior

APPENDIX C--STUDENT TESTS
Pre-test

Post- -test--Ecoiogy I
Post- -Test--Ecology 11

APPENDIX D--ATTITUDE SURVEY
APPENDIX E--STUDENT SIMULATION HANDOUTS .

APPENDIX F--FILM SOURCES .

61
62
73

74

112

113
116
123

128

133

137

LIST OF TABLES

TABLES PAGE
1. RESULTS OF PRE-TESTS AND POST-TESTS 37
2. RESULTS OF RESPIRATION TESTS 38
3. RESULTS OF PHOTOSYNTHESIS TESTS 39
4. RESULTS OF ATTITUDE SURVEY 4i

5. RESULTS OF EXIT INTERVIEWS
QUESTIONS 1 - 4 ALL STUDENTS 43

6. RESULTS OF EXIT INTERVIEWS
QUESTIONS 1 - 4 BY GRADE CATEGORY 43

7. RESULTS OF EXIT INTERVIEWS
QUESTIONS 5 - 7 44

vi

CHAPTER 1
INTRODUCTION

The traditional approach to most high school biology courses
is determined not by what makes sense to a student, but by what
made sense to a textbook author. Most courses and texts begin
with a review of chemistry, a unit on biochemistry, and a longer
unit on cells and their processes. Most courses next attempt to
cover genetics, reproduction. animals, plants. microorganisms.
ecology and evolution in varying sequences. This instructor.
teaching exactly that type of course. has long felt the burden of
too much content in our biology courses and too little
concentration on the really basic themes that underlie all
biology. This opinion is shared by many others. Dr. Paul Hurd

(1989) states:

This basic model of what a high school
biology course should be like has remained about
the same for more than a century, modified now
and then to reflect advancements in research.
Organs and tissues--their structure and
function-~continue to be the organizational
theme. In recent years extensions have been
added downward to the molecular level and upward
to include topics on ecology, population and the
biosphere. Whatever the level of organization,
the number of facts and terms increase with each
new edition of a textbook, and the significance
of these facts for understanding the realities
of life and living decreases.

The course used for this thesis was divided into four
basic units to reflect the need to organize material into
manageable categories: cells and their biochemistry,
reproduction. evolution and ecology. A great deal about the
biology of individual organisms or of phylogenetic groups
may be taught within the context of their overwhelming
similarities to each other in these four areas. Some of the

topics included in each of these units are:

Cells and Their Biochemistry

1. Size, shape and basic structures of cells

2. Transport of materials into and out of cells
3. Enzymes

4. Respiration

5. Photosynthesis

6

. DNA, RNA and protein synthesis
Reproduction

1. Cellular reproduction--Mltosls and Meiosis
2. Genetics

3. Animal sexual reproduction

4. Plant sexual reproduction

Evolution

1. Adaptation
2. Natural selection
3. Populations

Ecology

1. Cycling of elements in the environment

2. Limiting factors in the environment

3. Food chains/webs in communities

4. Taxonomy, structures, behavior of representative
organisms

After these units were decided upon, the problem became
the order in which to teach the topics. Cellular
organization seemed an obvious place to begin to a person
with many college hours in biology. However, the cell unit
with its strange and lengthy vocabulary and its reliance on
molecular or chemical concepts may have been the most
difficult of all those listed for a high school sophomore.
Perhaps the logical place to begin was with ecosystems,
which are visible, familiar and nonthreatening. This idea
is supported by the authors of one popular ecology text. In
the preface to this book they state:

Unlike some other sciences the subJect matter
of ecology is apparent to everybody: to the
extent that most people have observed and

pondered nature, most people are ecologists of
sorts. (Begon. Harper. and Townsend 1986).

The preface of the BS§S_§Leen_1en§LQn biology text

echoes this theme with a quote from Marston Dates of the
University of Michigan. Dr. Bates defines ecology as the
study of ”outer physiology" as contrasted to the ”inner
physiology‘I of the organism. After describing the
relationship between the two, he states, 'We stress the
outside rather than the inside on the assumption that this

is more familiar and more easily understood.” (BSCS 1987)

The opinion of this instructor was that ecology and
evolution together made up the two unifying themes of
biology. Ecology was used in this context to deal with the
relationship between organisms and their environment.
Evolution referred to that relationship as it changed by
adaptation over periods of time. Everything else in biology
could be understood in reference to these two aspects. In
the same preface to the ecology text quoted earlier the
authors 90 on to say:

If as T. H. Dobzhansky said, ’Nothing in biology
makes sense, except in the light of evolution’,
then, equally very little in evolution makes
sense, except in the light of ecology--that is,
in terms of the interactions between organisms

and their physical, chemical, and biological
environment.' (Begon, Harper, and Townsend

1986)

The decision was made to begin the biology course with
ecology and to end with evolution, as a result of the
philosophical thinking described above. This was an effort
to put the more abstract and unfamiliar concepts of
biochemistry, reproduction and evolution into a framework
that would make more sense to students. If students could
see the undeniable importance of photosynthesis, for
example, in the overall scheme of the ecosystem, it might
make that process seem more relevant and thus more easily

learned at a later time.

Based on that analysis, the teaching unit in ecology was
constructed as an introduction to biology. The concept of
an ecosystem was br0ken down into three parts: the abiotic,
the biotic. and the relationships between those two. These
three were equally appropriate at any level of the
ecosystem, such as, individual organisms, populations or

communities.

One of the most important abiotic principles to be
considered in this unit was the cycling of materials into
and out of living things in an ecosystem. Students had a
difficult time grasping the idea of organisms using and
reusing atoms. Even more difficult for them to understand
was that the atoms making up their bodies have been part of
other organisms for eons. Since it was not necessary for
students to know the details of a great many of these
cycles, this unit included only the water cycle, the

carbon/oxygen cycle, and the nitrogen cycle.

The second abiotic principle was the notion of limiting
factors. Some of the factors studied in this unit were
temperature, oxygen, pH, light, water, nitrogen, pressure
and trace elements. The discussion of limiting factors
began with Liebig’s Law of the Minimum and expanded to
include the idea that too much is as limiting as too little.
It was also important for students to understand the

interaction between several factors. For example, a

plant uses less zinc if it grown in the shade rather than
the sun, and grasses use more water when nitrogen in the

soil is low.

The third abiotic principle was the distribution of
energy in an ecosystem. This was almost impossible to
divorce from the biotic area since it involved food webs,
which inevitably included organisms. It was essential for
students to understand the sun as the source of all energy
for most processes on earth. Once the students had grasped
the idea that food chains begin with autotrophs, he/she
could follow the energy as it passed through food from one
organism to another. Only the energy which is stored in an
organisms’ body is available to its predators, as the energy
used in movement or as heat, for example, are converted into
unusable forms. Thus, the available energy decreases with
each step in the fooo chain which led the students
inevitably to the idea that energy does not cycle, as do the

elements, but must be renewed constantly.

The biotic aspects of an ecosystem consisted of all the
organisms in the community. These began with producers.
which create food from the incoming solar energy. Green
plants, of course, are the most important producers in most
ecosystems, and therefore, stress was put on their

processes, especially on photosynthesis.

The consumers, the middle steps in food chains or webs.
are mostly animals. Herbivores, predators, parasites and
scavengers were all included as consumers. The use of fooo
by all organisms as a source of energy and building material
was discussed as an example of their relatedness to one

another.

The decomposers, third and last in the food chain, were
defined as bacteria and fungi for this beginning course.
These are the recyclers of nature, returning the atoms of
the food chain to the abiotic component of the ecosystem.
Stress was put on the idea that these microbes receive their
own quota of energy in the respiratory processes they use,

some of which are anaerobic.

Probably the most important principle involved in the
ecology unit was the relationship between the abiotic and
biotic factors of any ecosystem. One can not study simply
the cycling of elements without also studying the
microbes and the other organisms involved in that cycle.
The concept of distribution of energy in the ecosystem is
intimately connected to the organisms in the food chain or
web. Students usually understood the influences of the
abiotic factors on organisms quite easily. However, they
very often found it difficult to grasp the other half of
that interaction, the organisms’ effects on their

environments.

Students also were introouced in this unit to the
process of thinking we refer to as the scientific method.
Most of the investigations in this unit were designed in an
attempt to allow students to pose problems, gather data, and

draw conclusions increasingly on their own.

Another corollary concept was taxonomy. Students had
to identify at least some animals, plants, and microbes in
order to understand the f00d chain. Taxonomy is utterly
boring unless tied to other ideas which make the naming of

organisms relevant.

The third and fourth corollaries were the related
processes of photosynthesis and respiration. These were
introduced in this unit as fundamental to plants and animals
and were taught in more detail in the unit on cells and
their biochemistry. Since these were considered uniquely
important to an understanding of the ecosystem, they were
chosen to be used in the evaluation of the ecology unit as

described in Chapter 3.

The teaching unit which preceded this thesis set out to
answer three central questions. 1) Would the students be
able to learn the underlying principles described in this
section? 2) Would understanding of food chains make the
later units on respiration and photosynthesis more relevant
and therefore easier to learn? 3) Would this unit with its
emphasis on lab and field work increase positive student
attitudes toward science in general and toward environmental

concerns as well?

CHAPTER 2

INSTRUCTION

OVERVIEW

The ecology unit, which is the central topic of this
thesis, was used with high school sophomores in a first year
biology course required for graduation. The students were
from a rural/suburban area in southern Michigan and were
almost exclusively middle class and Caucasian. The school
was small, so all sophomores took biology from the same
instructor. The total number of students in the course
varied from sixty to eighty. Class sizes averaged between
twenty and twenty-five. The abilities of the students
ranged from gifted to learning disabled, and there was no
ability grouping. Therefore, the entire range of abilities
could be found in any one section of biology. This made the
selection and writing of materials to be used by the whole
class challenging for the instructor. The use of several
methods, especially hands-on activities, represented an
effort to increase the interest level of all the students.

especially at the lower end of the ability range.

The ecosystem studied in this unit is a stream flowing

through the town within walking distance of the high school

10

11

in a fifty-five minute class period. The river was
partially diverted many years ago to provide a mill stream.
The mill stream flows into a dammed mill pond from which
water flows over the dam and quickly rejoins the river

water.

The unit is designed to begin at the start of school in
late August or early September and to continue until the end
of the first marking period, approximately eight weeks
later. The field work continued through the fall, and
students experienced field work in hot as well as
cool weather. Field work was also done in the winter and
again in the spring to allow students to understand the

effect of changing seasons on the stream ecosystem.

The eight week period was divided into two parts,
consisting of studies on abiotic and biotic factors. Each
of these involved field work, laboratories, reading
assignments, audiovisuals, lectures
and testing. It remained important, however. for the
teacher and students to keep in mind that all the concepts

taught in these two sections are totally interrelated.

12

OUTLINE OF UNIT

Ablotic Factors

A. Limiting Factors

\Immwa"

‘OQ

10

11.
12.
13.
14.
15.
16.
17.

18.
19.
20.

Handout--Reading assignment (See Appendix A)

Class discussion of various limiting factors

Lab: Limiting Factors for Algae (See Appendix B)

Class Discussion: Writing Laboratory Reports

Handout: Writing Laboratory Reports

Class Activity: Graphing

Lab: Effect of Temperature on Dissolved Oxygen
Concentration (See Appendix B)

Lecture: pH

Lab: pH of Common Household Substances (See
Appendix B)

Film: hittg;_gain (See Appendix F)

Class Discussion: pH as Limiting Factor

Field Work: Mill Stream

Field Work: River

Lecture: Averages and Deviations

Group Work: Figuring Averages from Stream Data

Lab: Organisms and pH (See Appendix B)

Lab: Testing for Common Ions in Water Samples (See
Appendix 8)

Film: greatgat_Lakes (See Appendix F)

Film: Qggan_QL_LLgnt (See Appendix F)

Film: Kn&3£;911§13 (See Appendix F)

B. Cycling of Elements

.AUNH

C. Test:

Lecture: Cycling of Elements

Reading Assignment: Chap. 704—709 Mgdern_fiigiggy

Film: intg_;ng_Abys§ (See Appendix F)

Film: WWW
Cycles. (See Appendix F) Statement from film:
l'Living things only borrow the chemicals (atoms)
of which they are made“. Each student is to
write a paragraph explaining that statement.

Ecology I--Abiotlc Factors

Biotic Factors

A. Food Chains

Reading Assignment: Ch 49 Moggnn_fiiglggy
Lecture: Food Chains and Food Webs

Handout: Food Web Assignment (See Appendix A)
Predator/Prey Simulation Game (See Appendix E)
Lab: Biochemical Oxygen Demand (See Appendix B)

. Film: WW (See
Appendix F)

QNQOINH

B Organism Identification

1. Lab: Microscope Introduction (See Appendix B)

2. Reading Assignment: Ch 14 Mode:n_BLQLQg1

3. Taxonomy Game/Belly Taxonomy

4. Taxonomy Activity: Sharks/Salamanders/Leaves:
Using a Dichotomous Key

5. Assignment: Making A Key for Mythical Animals

6. Field Work: Collecting Mill Stream “Critters"

7. Field Work: Collecting River “Critters“

8. Lab: Analysis of Feeding Groups of Stream

Macrolnvertebrates (See Appendix B)
9. Lab: Live Crayfish Observation (See Appendix B)
10. Lab: Crayfish/Insect Comparison
11. Reading Assignment: Ch 30, 31, 32 Mgggnn_fliglggy
12. Handouts: Worksheets on Ch 30, 31, 32
13. Lab: Observation of Algae and Protozoa
14. Film: maytly (See Appendix F)
15. Film: L11g_in_Lg§t_§;ggk (See Appendix F)
16. Film: Dragonflx (See Appendix F)
17. Lab: Schooling Behavior (See Appendix B)

C. Test: Ecology 2--Biotic Factors

14

ANALYSIS OF LABORATORIES

The laboratory exercises in this unit can be divided
into those which are inquiry-based and those which are not.
Some techniques, such as microscope use or pH measurement
were easier to teach using a lab format with questions,

drawings, etc. rather than an hypothesis-based format.

All the inquiry labs based on the scientific method
used the same format. The introduction set up the problem
to be studied and gave the student information. The student
was then asked to write three possible hypotheses concerning
the problem and to choose the hypothesis which he/she felt
was the best. Standard materials and methods sections then
followed. The student was asked to make his/her own data
tables, graph the data if appropriate, and write
observations in the data section of the lab report. Finally
the student was instructed to draw a conclusion referring

back to the hypothesis chosen.

Prior to handing out the materials and methods
sections, the students were asked to suggest possible ways
to set up experiments to test their hypotheses. Their

activities required guidance on the part of the teacher, but

15

usually the students came very close to the lab as it was
written. This gave them ownership in the lab and a feeling

of doing “real science" as opposed to following directions.

Lab reports were written for all the “scientific
method' labs. Students were helped by written suggestions
from the teacher for improving their writing or their
methods. The effectiveness of the labs was evaluated using
the students’ written reports. Students disliked writing
the reports, but their writing did improve over the course
of the unit. Most of them saved each report and used the
written suggestions when they were preparing the next

report .

The following is an analysis of each of the labs used

in this unit:

1. LIMITING FACTORS FOR ALGAE

The purpose of this lab was to deal with a limiting
factor problem. The algae used were scraped from aquarla to
make a standard population from which the students initially
drew measured amounts. The algal growth was measured using
a Spec 20 set at a wavelength of 430, and the absorbance was
graphed against the concentration of nitrogen used in each
sample. Student results indicated that the algae colonies

grew fastest with the middle range of fertilizer. The lab

16

was effective in teaching the concept that too much of a
needed substance can be as limiting as too little. The

student handout for this lab is included in Appendix B.

2. EFFECT OF TEMPERATURE ON DISSOLVED OXYGEN CONCENTRATION

There were two reasons for using this lab in this unit.
The first was to acquaint the student with the technique for
measuring dissolved oxygen (DO) using a kit available from
Hach Co. of Loveland, Colorado. The second was for the
student to gain an understanding of the interrelationships
among limiting factors. A common misconception among
students was that the warmer the water is, the more living
things it is likely to contain. Typical student results
indicated that warmer water dissolves more oxygen than
colder water. These results came as a surprise to many
students. Any temperatures may be chosen for convenience as
long as they are widely different from each other. In order
to get best results an aquarium aerator was used to bubble
the water at each temperature for an equal amount of time.

The student handout for this lab is included in Appendix B.

3. PH OF COMMON HOUSEHOLD SUBSTANCES

This was a technical rather than an inquiry-based lab.
This lab introduced the student to the types of pH

measurement devices available and to help them understand

17

the range of pH which they encounter in everyday living.
They were given a variety of substances such as vinegar,
milk, cleansers, window cleaners, lemon Juice, alcohol or
bleach and were asked to measure them using the laboratory
pH meter and the portable meters they would be using in the
field. One benefit of this comparison between meters was
that the students became aware that not all meters give the
same reading from the same sample. They tended to believe
any numbers read from a meter are always correct. The

student handout for this lab is available in Appendix B.

4. ORGANISMS AND PH

This lab was used to introduce the students to the pH
buffering of many biological materials. pH can be a
limiting factor for many organisms, but because of the
inherent ability of their proteins to buffer, it often is
not. The students were asked to add measured amounts of HCl
and NaOH to tap water and to make data tables and graphs of
the results. They were then asked to do the same thing
using egg white, gelatin, liver or potato homogenate. A
third part asked the students to make the same experiment
using a buffer of pH 7. Student results indicated that the

pH changed more slowly in the buffered solutions than in

18

pure water. Most striking to the students were the results
with the biological materials which were more similar to the
buffered solutions than to the water. The student handout

for this lab is included in Appendix B.

5. TESTING FOR COMMON IONS IN WATER SAMPLES

The methods in this lab were qualitative rather than
quantitative: nevertheless the students became aware of the
minerals in various water sources. Actually most students
realized that the water sources had high mineral content, as
they live in an area of hard water. Students were asked to
test mill stream, river, distilled and tap water. Also
students could bring in water from a home source (well,
spring, stream) for testing. The methods used for testing
were taken from the water quality section of Chemgom (1988).
Since the tests involved color changes or precipitates, this
lab was written to use microscale chemistry techniques.
These methods allowed the students to repeat each test
several times in a short period and required much less
investment in chemicals. The ions tested were ferric iron,
calcium, chloride, and sulfate. For each test a reference
solution was provided so that the students might learn the
appearance of a positive test. The student handout for this

lab is included in Appendix B.

19
6. MICROSCOPE INTRODUCTION

The students in this course had very little experience
with microscopes and needed to be taught the proper
techniques of microscope use. This lab introduced them to
care and cleaning of the instruments as well as to the
concepts of magnification, field of view and depth of field.
They were introduced to binocular dissecting microscopes as
well as to the standard monocular instruments. Both of
these were used in subsequent identification of stream

organisms.

7. ANALYSIS OF FEEDING GROUPS OF STREAM MACROINVERTEBRATES

The objective of this lab was to quickly assess the
food base of the stream by focusing on the roles played by
the macroinvertebrates present. Students were asked to
collect samples of the leaf litter on the bottom of the
river. These samples were returned to the lab and
refrigerated. The following day organisms were identified.
The key used in this lab was given to participants in the
Frontiers Program at Michigan State University by Dr. Mike
Klug of Kellogg Biological Station. According to Cummins
and Wilzbach, the original authors of the key, about 80-90%
of the organisms found in stream leaf litter can be
classified using this key. Emphasis in the key was on

common names of organisms and on their roles in the fooo

20

chain, rather than on formal taxonomic identification. This
was the first opportunity for many students to use any type
of biological key. The organisms found included small clams
and snails, tiny Crustaceans, insect larvae/nymphs and
worms. Most of the organisms survived the collecting and
subsequent refrigeration quite well, probably because this
was done late enough in the fall that the river water
temperature was close to that of the refrigerator. It would
have been preferable to identify the organisms the same day
as they were collected, but schedule constraints made this
impossible. The alternative of having the teacher collect
the samples before the identification class would not have
allowed the students the fun of collecting their own
samples. This was probably the most popular lab involved in
this unit. The students giggled and resisted touching the
leaves at first, but that soon changed when they began
finding living, fast-moving little “critters“. This lab,
using the same collection and identification paradigm, was
repeated in the winter and again in the early spring.
Students predicted that all these “critters“ would be killed
by the winter temperatures, without thinking of the disaster
that would have been to the species involved. Contrary to

their expectations. they found the same organisms not only

21

present in the colder winter water, but larger yet each time
the examination was done over the course of the school year,
Perhaps they were surprised enough to change their

misconceptions about the lifelessness of winter streams.

8. LIVE CRAYFISH OBSERVATION

The purpose of this lab was to familiarize students
with the anatomy and behavior of the crayfish, a common
invertebrate in the stream. Students were first asked to
identify the maJor external structures of the crayfish and
to predict the functions of each appendage from the crayfish
behavior. Each group of students then observed the reaction
of the crayfish to the following stimuli: a rock in the
tank, touch, light, saturated salt solution and India ink.
At no time was any crayfish allowed to be inJured or left in
an uncomfortable situation for any length of time. The
crayfish used were captured by the students from the river
being studied and were released following the lab. The

student handout for this lab is included in Appendix B.

9. CRAYFISH/INSECT COMPARISON

In the preceding macroinvertebrate lab, the students
found many crustaceans and insects in the leaf litter,
making arthropods a focus for the stream analysis. In this

lab students were given preserved specimens of crayfish and

22

grasshoppers, as typical representatives of their classes,
and were asked to compare them. This was the only activity
that approximated dissection in the entire introductory
course. The observations were made on the exterior of the
specimens only. Internal observations were made with the
aid of diagrams. As a result the specimens were used from
class to class and indeed from year to year. The time it
would have taken to actually dissect either crayfish or
grasshopper seemed inappropriate to the obJective which was
to compare rather than to identify specific structures.
This lab provided a good compromise between observation and
dissection. The student handout for this lab is included in

Appendix B.

10. OBSERVATION OF ALGAE AND PROTOZOA

In this lab students were given the opportunity to
become familiar with the common types of algae and protozoa
found in the stream. Students were given prepared micro-
slides containing six types of algae and assorted types of
protozoans as well as colonies of living plankton gathered
from river, ponds, etc. and were asked to identify the basic
types. Stress was placed on roles in food chains rather
than on sophisticated identification. Common names were

used wherever possible. The keys used were those borrowed

23

from the school library, but this instructor would like to
write keys for this lab similar in intent to the one used

with macroinvertebrates.

11. SCHOOLING BEHAVIOR

Students rarely encountered any fish in all the field
work at the river and mill stream. Trout and bass are known
to be present, but the students were too exuberant and too
numerous to have much chance to find them. This lab gave
students the opportunity to work with the maJor type of
vertebrates, fish, in the stream. Tropical fish were used
in the lab because they tended to survive life in the
aquarium better than those from the stream. However, this
did make the lab fairly expensive. The behavior of tropical
fish with visible markings was compared to that of unmarked
fish. Fish were placed in aquaria large enough to
accommodate large beakers covered with cheesecloth. The
school of fish was placed in the beaker and one specimen
fish was allowed free in the aquarium. Students monitored
the number of seconds spent swimming in the sector of the
beaker and the number spent swimming away from the rest of
the school. Variations to this procedure were then allowed.
Typically the marked fish spent more time swimming with the
'school' than did the unmarked fish. The student handout

for this lab is included in Appendix B.

24

ANALYSIS OF FIELD TECHNIQUES

Discipline of students in the freedom of the field trip
was of maJor concern initially. This turned out to be of
little consequence. The students walked to the day’s site
in a group and began their assigned tasks right away. At no
time did anyone leave the site or cause any problems beyond
high spirits. The reason for this responsible behavior on
the students’ part was probably that they saw the tasks as
real science and were interested in the results. Another
reason could also be that they knew field trips would become

an extinct activity if they misbehaved.

An unforeseen difficulty did arise, however, which
could have presented a real problem without the help of the
principal of the high school. A young woman with cerebral
palsy was in one of the classes. She simply could not walk
the few blocks to the river, and it was felt the instructor
should walk with the other students rather than driving.
The principal of the high school agreed to drive her to the
river and return to pick her up. Without his help this

could have been a real problem.

Each class of students was divided into six groups.
which were lettered A - F for all field work. Groups
averaged four students each. Tasks were divided into three
sets with two groups assigned to each set of tasks. For

example, groups A and D could be assigned to measure DO;

25

groups B and E could be assigned to measure depth, pH,
temperature and flow rate; groups C and F could be assigned
to measure nitrate. The groups would be rotated on the next
field trip so that each group of students had an opportunity
to do every test at least once. Each group was given a data
sheet for recording their data at the stream. The data
sheets were signed by each person in the group and turned in
after the group posted their data on the class data table on
the classroom bulletin board. The next day this data could

be averaged from all three classes and deviations figured.

The following is an analysis of the procedures assigned
to the students on the field trips for the past two years.
As more funds become available and more equipment can be

purchased, more procedures will be added.

1. DISSOLVED OXYGEN.

Because of limited funds only two dissolved oxygen (DO)
kits were available. Each of the two groups of four
students assigned to measure DO were given a kit. The
instructions that came with each kit were removed, enlarged
(the print is small), and duplicated. This was a good
decision because chemicals were spilled on some of the
instructions and they had to be replaced. Most of the
students had little problem following the instructions.

They measured the D0 of water at the surface and also of

26

water near the bottom of the mill stream. The two groups
assigned to DO shared a waste bucket with those assigned to
nitrate so that no chemicals were poured into the stream or
on the ground. Typical student results for DO were in the
range of ten parts per million in the fall, increasing to

eleven ppm in the winter.

2. NITRATE

Hach kits were used in much the same way as in the DO
test. Low range test kits worked quite well as the stream
carried only a small amount of nitrate in spite of the
agricultural nature of the area. Typical student data were

in the range of .01 - .05 ppm.

3. DEPTH

The river is shallow enough for wading, and thus meter
sticks were used to measure depth. In the mill stream,
however, the depth is several feet so wading was not
possible. There was, however, a bridge across the mill
stream which allowed students access to the center of the
stream. A long wooden pole was marked off to use as a
measuring device from the bridge. In all cases the students
marked a line across the stream and made several
measurements. They were able to profile the bottom with

greatest and average depth.

27

4. TEMPERATURE

A standard laboratory thermometer was used for
measuring temperature at the surface. Temperature at depth
was measured using a small thermometer attached inside the

water-collecting apparatus.

5. pH

Two portable pH meters made by Corning were purchased.
The accuracy of these was found to be within .2 pH units of
the laboratory pH meter. The portable meters were wonderful
for students to use at the stream because they gave a
digital readout with no colors to compare. The meters
seemed to be quite sturdy and student-proof. Typically the

students measured the pH of the stream between 8.0 and 8.5.

6. FLOW RATE

The students marked off a thirty-foot section of
stream, in this unit thirty feet. The time it took for a
ball or orange was allowed to float in the current for that
distance was timed in seconds. The feet per second could
then be calculated and converted into miles per hour. An
orange was the most accurate measuring device, as it floated
right in the current, not above or below. However, as this

unit covered several weeks, a tennis ball was used because

it did not decompose. Stopwatches were used for timing.
Students had no difficulty retrieving the ball from the
river because they could wade. In the deeper mill stream
the ball was always started upstream from the bridge and a
long-handled net was used for retrieval. This test was the
most enjoyable task in the field work for the students.
They liked watching the ball (and throwing it at each other
occasionally), and they enjoyed knowing the speed of the

current and comparing it to their own walking speed.

ANALYSIS OF SIMULATIONS

Some concepts lend themselves more easily to simulation
activities than to actual lab or field work. Two such

simulations were used in this unit.

1. PREDATOR/PREY SIMULATION.

This activity compared the population of mice (prey)
and owls (predator) in a wooos over a span of several
generations. The woods was an area of the classroom lab
tables marked off with masking tape. The squares
representing mice and owls were duplicated so that plenty
were on hand. Mouse squares, especially, were needed in
large numbers! The instructions told the students to drop
the owl from a certain height, and any mouse square touching

the owl was 'caught'. Each remaining mouse was allowed to

29

reproouce by adding more mouse squares. Each owl reprOduced
only if it received three mice. The data was recorded on a
table and the two populations were graphed at the conclusion
of the activity. The activity reinforced the concept of
interdependence between predator and prey. Many students
dislike predators, believing the IBambi myth“. It was
helpful for them to see that the mouse population was not
exterminated even when the owl population was high. The
only problem with this activity was that it was
time-consuming and the counting of the mouse squares was
tedious at times. The results, however, were so good that

the activity will be used again.

2. TAXONOMY GAME/BELLY TAXONOMY

The Objective of this activity was to allow the
students to increase their understanding of the encompassing
nature of a kingdom, a phylum, a class, an order, etc.

Index cards were marked with selected names of kingdoms,
phyla, classes and orders. Each student selected one card
at random and pinned it to his/her clothing (hence the name
"Belly Taxonomy“). The class was given time to look up the
groups represented in the appendix of their book so that
they knew to what type of group each name referred. The

”classes“ used string to gather all their "orders“. The

30

"phyla“ gathered all their “classes“ (and “orders“) and the
“kingdoms“ gathered all their divisions within one big
string circle. Usually two or three kingdoms were used so
the entire class ended up in two of three large groups. It
was possible to play the game twice in one hour and if
different cards were used, the students enjoyed it. It had
long been a problem to make students understand that if an
animal belongs to the class Mammalia, for example, it MUST
belong to the phylum Chordata. Somehow in the chaos of this

activity, many students seemed to get the message.

ANALYSIS OF FILMS

The purpose for using the films in this unit was to
allow the students to observe aquatic environments at great
distances from Michigan. It was not possible to take
students on field trips to the ocean or even to the Great
Lakes, and yet it was thought to be important for them to
understand that these other ecosystems have much in common

with the familiar hometown river.

The films listed in this thesis were used over the two
year period. However, not every film was used each year

because of scheduling problems. The average number used in

31

any one year was about eight. All the films discussed below
were of value in teaching this unit. The students enjoyed

them, and they made a welcome break from lab and field work.

A list of the sources for these films is found in
Appendix F. They are all in the library of the Calhoun

Intermediate School District and available to all county

schools.

1. BLIIER_RAIN, 22 min. Recommended for grades 7-12.

This film discusses the effects of acid rain, the
causes, and the solutions now available. It centers
primarily on lakes in Scandinavia and Canada. It really
brings home the point that acid rain is a problem in
relatively nonlndustrlal areas and is a major contributing

factor to pollution of drinking water.

2. GREATESI_LAKES. 30 min. Recommended for grades 9-12.

This film deals with the geographic history of the
Great Lakes, the latest scientific approaches to the current
environmental problems facing the lakes, and the possible
future problems as well. In Michigan it would seem to be
necessary to drive home the point that any factor affecting

the surface or ground water also affects the lakes.

32

3. QCEAN_Q£_L1§HI. 58 min. Recommended for grades 9-12.

Part of the series Atlanti§_3e§im

This long film is worth the time as the photography is
so well done. It deals with the effects of winds and
currents on the behavior of sea life near the surface. The
students are able to get a glimpse of aquatic life in an

ecosystem very different from the stream in this unit.

4. WAIER_£RLSIS. 57 min. Recommended for grades 9-12.

Water prOblems in the Adirondack Mountains, on the
Mississippi River, and in California are discussed. Many of
the controversial issues are those still in the news.
Troubles highlighted include acid, rain, overdraftlng of
aquifers, drought, disinfecting methods that may cause

cancer, toxic industrial waste.

5. 1NIQ_IHE_ABXS$. 58 min. Recommended for grades 9-12.

Part of a series AILANII§_REALM

This was one film that the students remembered and
referred to during the entire year. It deals with high
pressure, low temperature, and complete darkness as extreme
examples of limiting factors. Many of the organisms
photographed have never been seen by these students before.

Especially interesting are colonies of bacteria living

33

around “black smokers“ and using chemosynthesis of sulfur
compounds as producers in the food chain. It is a long

film, but well worth the time.

6. -- -- --

15 minutes. Recommended for grades 7-12.

This film includes a good discussion of element cycles
in ecosystems. The music is a little too loud and
distracting. The quote “Living things only borrow the
chemicals (atoms) of which they are made.“ was used as the

basis for a student writing assignment.

7. COMMUNITIES QE LIYINQ IflINQS--D--g[:§g§ gag
Qceans::$tneams_and_Lakes 15 minutes per section.

Recommended for grades 7-12.

Part 1 discusses organisms that live in salt creeks
where the environment varies with the tide from mud flats to
being under water. Organisms mentioned are fiddler crabs.
blue crabs, hermit crabs, shrimp, barnacles, anemones.

oyster toads (fish), and snails.

Part 2 discusses organisms that live in lakes where
there is little movement of the water, and oxygen levels are
relatively low. Organisms mentioned are flatworms, hydra,
dragonfly larva, segmented worms, rotifers, and bloodworms

(insect larva). The film also discusses mountain streams

34

where currents are a large factor, and oxygen levels are
high. Organisms mentioned are dragonfly larva. stonefly

larva, mayfly larva, and crayfish.

e. counuuzrins a: nyzug IBINQS-—Q--Enengy

3 parts--15 minutes each. Recommended for grades 7-12

Part 1 (Origins) introduces chlorophyll, phototropisms,
photosynthetic reactions, leaf structure and arrangement,
and bacterial chemosynthesis. The quote “Plants are the
gateway for chemical energy to enter the world of living

things“ was used for class discussion following the film.

Part 2 (Use and Storage) introduces uses for energy in
specific animals, respiration reactions, mitochondria. plant
starch storage. animal fat storage, and passage of energy

through food chains.

Part 3 (Energy Distribution) introduces food chains.
dependence on plants, and food webs. The quote “The
ultimate use of energy is in reproduction in which it is
passed to the young who must in turn get their own further

energy‘ was used in class discussion following the film.

35

WW

13 minutes. Recommended for all ages

This film follows the life cycle of dragonflies from
egg to adult. Time lapse photography shows their
outstanding acrobatic ability. Excellent use of concept of

body adaptations to life style.

10. LI£E_1N_LQSI_§REEK 15 minutes. Recommended for grades
7-12.

This film uses underwater photography to show the
ecology of three fresh water ecosystems. It introduces the
concepts of habitat, adaptation. niche, population, food

chain, transfer of energy.

11. W- 15 minutes.

Recommended for grades 7-12.

This film discusses the mayfly life cycle very clearly.
It portrays the mayfly as a vital part of food chain and as
an important indicator of water quality. It was especially
interesting to the students in this unit because they found

so many mayfly nymphs in the stream leaf litter.

CHAPTER 3

W

Evaluation of this new unit was accomplished in a
variety of ways. Pre- and post-tests were given to measure
the content learned. Pre and post attitude surveys were
used to measure attitudes toward science and toward
environmental issues. Interviews were done with randomly
selected students at the end of the year. Comparisons were
made of grades on subsequent topics (respiration and
photosynthesis) between the two years covered by this unit

and the previous three years.

PRE-TESTS AND POST-TESTS

The pre- and post-tests are included in Appendix C.
All of the questions from the pre-test are found in the
post-tests, but other questions have been added as well.
The pre-test was administered in the first week of school in
the biology classes. The post-test was divided into two

sections: abiotic and biotic. The abiotic test, which is

36

37

called Ecology I, was given mid-way through the unit and the

biotic test, which is called Ecology 11, was given at the

800.

The results are shown in the following tables:

 

 

 

Table 1. RESULTS OF PRE-TESTS AND POST-TESTS
Pre-test Ecology I Ecology II
Highest
Class Possible Mean 8.0. Mean 8.0. Mean S.D.
Score
3rd Hr 100 38.6 8.0 69.5 12.8 75.2 12.6
5th Hr 100 36.0 1.0 75.7 11.5 65.7 15.4
6th Hr 100 43.4 9.8 74.1 14.3 75.4 16.7
Total 100 39.8 9.4a 72.7 13.1a 73.2 14.9a

 

a. Significant at the 0.001 level

COMPARISON TO PAST YEARS

Prior to 1986 an ecology unit was taught at the end of
the biology course. This previous unit included no field
work and was often squeezed into the final days of school

when students were busy preparing for final exams.

The “new“ ecology unit was taught at the beginning of
the year for two years (1989-90, 1990—91) before this thesis

was written. In both of these years the cell unit followed

38

ecology, and in time the students were taught and tested
over the processes of respiration and photosynthesis. The
teaching modules and the tests on these cellular processes
had been virtually unchanged for a number of years. This
allowed a comparison to be made between the achievement of
students in the years i989-91 with that of students in the
years 1986-89. The comparison was based on the percentage
scores for the three years prior to the implementation of
the ecology unit as an introduction. The results are shown

in the tables that follow:.

Table 2. RESULTS OF RESPIRATION TESTS

 

 

School Year Mean Percentage 3.0.
1986-87 55.4 17.9
1987-88 54.6 17.2
1988-89 53.2 21.7
Total 1986-89 54.4 18.9 a
1989-90 60.9 18.6
1990-91 63.4 16.6
Total 1989-91 62.2 17.6 a

 

a. Significant at the 0.001 level

39

Table 3. RESULTS OF PHOTOSYNTHESIS TESTS

 

 

School Year Mean Percentage 8.0
1986-87 61.2 17.3
1987-88 59.9 16.2
1988-89 64.8 15.9
Total 1986-89 61.7 16.5 a
1989-90 68.2 16.1
1990-91 70.9 14.3
Total 1989-91 69.6 15.2 a

 

a. Significant at the 0.001 level

ATTITUDE SURVEYS

The attitude survey used was prepared as part of the
research done by Sue Townsend, Jerry Kovach, Joe Kuester and
this instructor at the Kellogg Biological Station as part of
the Environmental and Behavioral Ecology workshop for high
school teachers sponsored by National Science Foundation and
Michigan State University. The questions came in part from
a survey written by Becky Stout (1986) in a Master’s Thesis
for Michigan State University. Other questions were added
by the four researchers in an attempt to test for the
specific attitudes of high school students toward science
and toward environmental issues. It was recognized by the

authors of this survey that attitudes are difficult to

40

change and perhaps even more difficult to measure. This
survey needs to be revised, especially as to vocabulary.
For example, this instructor found that some of the lower
ability students did not recognize the word “inhabited“ in
print, although they would have understood it had it been

given orally.

The survey gave students a choice of two opposite ideas
and asked them to choose between them on a scale of 1-5.
Those ideas considered negative and positive were mixed:
that is, 5 was not always positive. In the scoring,
however, those were turned around so that 5 became the most

positive score and 1 became the most negative.

The survey was given to the students in their sophomore
English classes during the first week of school. The
cooperating English teacher did not tell them that the
results would be used in their biology classes. This was an
effort to keep them from biasing the results by worrying
about the instructor’s feelings. At the end of the unit the
survey was repeated in English class. Three sections of the
survey were appropriate to this unit. 1) questions on
science as a whole, laboratory activities, working in teams
to solve problems, and the scientific method. 2) questions
on science careers. 3) questions on the degree of pollution.

water quality, and importance of the local rivers. The

41

actual survey questions are included in Appendix D, and the

results of the three sections of the attitude survey are

shown in Table 4.

Table 4. RESULTS OF ATTITUDE SURVEY

 

 

Section
of Pre Post

Survey Mean S.D. Mean S.D.
All Science 3.3 0.44 a 3.5 0.36a
(1-28, 66-85)

Science Careers 2.3 1.00 b 2.8 0.75b
(83-84)

Local Rivers 3.4 0.66 c 3.6 0.44c
(61-65)

 

a. Significant at the 0.01 level.
b. Significant at the 0.01 level.
c. Significant at the 0.10 level.

EXIT INTERVIEWS

Twenty-four of the sixty-five biology students were
interviewed at the end of the school year. This group was
chosen at random and consisted of six students from each of
four grade categories (A. B, C and D) based on the first
marking period during which the class completed this ecology
unit. There were no students who failed this unit. The
interview group was also selected by sex: half were male

and half were female.

42

The students were reminded of the four units covered in
biology that year. Each was then asked a series of seven
questions and was given a chance to make comments which were

also recorded. The questions asked are the following:

1. Which of the four units did you enjoy most?
2. Which of the four units did you enjoy least?

3. In which of the four units did you learn the most (that
you did not already know)?

4. In which of the four units did you learn the least (that
you did not already know)?

5. Another way to build a biology course is to begin with
cells, work up to animals and plants. and end with
ecology in the spring. Would you rather have had the
ecology (stream study) unit in the fall or in the
Spring?

6. Do you think learning about food chains, producers,
consumers and decomposers in advance helped you learn
about photosynthesis and respiration later?

7. We divided the year into units and jumped around in the
book quite a lot. We also did quite a lot of work that
was not in the book at all. Did you like this or would
you have been more comfortable going through the book
chapter by chapter so that you would have known more
what was going to happen next?

43

The results of this survey are given in the following table:

 

 

 

 

 

Table 5. RESULTS OF EXIT INTERVIEWS.
QUESTIONS 1 - 4 ALL STUDENTS
Questions Percentage Answering Per Unit

Ecology Cells Reprod Evolution
1 Enjoyed Most 50.0 4.2 29.2 16.7
2 Enjoyed Least 8.3 62.5 12.5 16.7
3 Learned Most 16.7 16.7 33.3 33.3
4 Learned Least 16.7 33.3 33.3 16.7
Table 6. RESULTS OF EXIT INTERVIEWS

QUESTIONS 1 - 4 BY GRADE CATEGORY
Questions Percentage Answering Ecology
A B C D

i Enjoyed Most 50.0 16.7 66.7 66.7
2 Enjoyed Least 0 16.7 16.7 0
3 Learned Most 16.7 0 33.3 16.7
4 Learned Least 16.? 33.3 16.7 0

 

44

Table 7. RESULTS OF EXIT INTERVIEWS--QUESTIONS 5 - 7

 

Percentage Answering Per Question

 

Grade 5 6 7
Category Fall Spring Yes No Unit Chapter
A 83.3 16.7 66.7 33.3 100.0 0
B 83.3 16.7 66.7 33.3 100.0 0
C 100.0 0 83.3 16.7 100.0 0
D 100.0 0 50.0 50.0 66.7 33.3
ALL STUDENTS 91.7 8.3 66.7 33.3 91.7 8.3

 

Many of the students interviewed found it difficult to
choose among the units covered in the course. They only

made a choice when pushed to do so by this instructor.

Some of those students who stated that they enjoyed the
ecology unit most gave the following comments:

“i liked experimenting with the river."

”i liked being outside.“

“It made biology real.“

“I liked it that we got to do things for ourselves.“

“I really liked doing the DO test.“

'It didn’t seem like work.‘

One of those students who stated that they learned the
most from the ecology unit said, “I learned more because I

actually did it instead of just learning what other people

had done.“

45

Two stuoents commented on why they would have preferred

the ecology unit in the spring:

were

'It would have put the least concentrated (unit) at the
end of the year.“

'It would have made more sense to go from cells up to
the environment.‘

Comments from students who liked the unit in the fall

the following:

“It let us see the same things (organisms) as they
started out all the way through the year.“

“It was an exciting way to start the class.“

“It was a fun way to start the class.“

I'It made the class not boring at first.“

“It would be too hot in the spring.“

“It let you mix up the hard stuff with the easy Stuff
so it wasn’t all at one time.“

“It taught us things we needed to know later in the
class.“

'it made us look forward to the rest of the year.“

Students who thought they had been helped by the

ecology unit when they had to learn photosynthesis and

respiration later on made these comments:

"It made us understand what was going on.“
"It let us know why we need to know that stuff."
“It showed us why it was important.“

Finally students commented as follows on the unit

format rather than a chapter-by-chapter type of class:

"It made us pay more attention rather than relying on
the book.:

"It made it more interesting.‘

“It made it funneri'

46

TEACHER OBSERVATIONS

In addition to these comments during the interviews,
this instructor made a great many observations of student
behavior during the unit. One of the most obvious was that
students could not wait to get to the river. They were
extremely disappointed if a field trip had to be cancelled
due to a downpour They came equipped with what they
considered to be appropriate clothing on the days of
scheduled trips. Very few were absent or tardy during the
ecology unit. They worked well together in the small
groups, each person taking some responsibility for the
results. The students seemed to have less apprehension
about their own abilities to do well in biology compared to
students in other years. They were interested in the stream
and asked questions. They challenged things they heard in
films, from their teacher or on television. They brought in
reams of newspaper clippings and magazine articles
concerning environmental topics. Perhaps best of all, they
seemed to begin to see their teacher as a person, one who
got hot or cold, thirsty, tired and wet right along with
them, but who had a passion for biology. This may have been

the most important result of the field work. The rest of

the year went more smoothly than at any other time in a
twenty-three year career, and it seemed to be because each
class was coalesced into a cooperative unit with the

instructor part of that unit.

CHAPTER 4

Three questions were asked in the intrOduction to this
thesis concerning the efficacy of this unit to promote
learning and to induce attitudinal changes. The tests and
surveys used to evaluate the unit and to answer these

questions are discussed in Chapter 3.

LEARNING OF ECOLOGICAL CONCEPTS

The first question dealt with the effectiveness of this
unit in teaching ecological concepts. Pre-test and
post-test data indicate that the unit was very effective.
The statistical differences between the pre-test and
post-test scores were highly significant. Students were
able to learn the concepts involved. Perhaps one of the
reasons for the success of the unit was its length. Too
often a unit on ecology is squeezed into the last two weeks
of school in the spring. In this unit time was taken to
make sure that essential facts were learned and concepts

were understood.

48

49

A second reason for effectiveness was that this unit
did not rely on just one method of teaching. Many films
were used and many of the labs produced highly visible
results, assisting those students who were visual learners.
Labs and field work also provided an instructional tool for
those students who needed to manipulate things in order to
learn. And last, of course, traditional lectures and class
discussions were used to help those who found it easier to

learn in an auditory mOde.

A third reason for the success of the unit in teaching
ecological concepts was the motivation of the students to
learn. It is unreasonable to expect students to learn
isolated facts for which they see no relevance. This unit
provided material to which the students could relate, and
they became confident of their abilities to succeed. They
were interested in the river and they found the activities

fun. When students want to learn, they generally do.

LEARNING OF RESPIRATION/PHOTOSYNTHESIS

The second question posed in the introduction concerned
the effect of the ecology unit on later learning of related
topics. Student test scores on respiration and
photosynthesis were compared over a five year period. The

scores from the latter two years of that period, during

50

which the ecology unit was used as an introduction to
biology, were significantly higher than those from the prior
three years. The mean on the respiration test from the
latter two years was 62.2% which was an increase from the
54.4% of the prior three years. The mean score on the
photosynthesis test increased from 61.7% to 69.6%. Both of
these increases are significant at the .001 level. The
conclusion that the ecology unit did indeed make a
difference on later learning is also supported by the
students’ answers to question 6 in the exit interviews.
Fully two-thirds of the students interviewed indicated that
they had been helped in understanding the later biochemical
units by first learning the concepts of food chains and
energy transfer in an ecosystem. In this instructor’s
opinion the reason has to be that students could see the
relevance of the abstract work in cell biochemistry..
Students have always asked why it was important for them to
know any details of the Kreb’s Cycle or of the ability of
chlorophyll to absorb photons of energy. They asked those
kinds of questions much less often during the two years
covered by this thesis. It would be interesting to know if
the ecology unit also helped in student learning of other
related material. For example, the large unit on evolution
contained a great deal of material on population growth

limits. It would be interesting to compare the scores of

51

those students who had already learned thoroughly the
concept of limiting factors with those who were not exposed
to it. Unfortunately, the evolution unit was also
completely rewritten and enlarged at the same time as the
ecology unit so there are no scores available for

comparison.

ATTITUDINAL CHANGE

Much of the educational literature seems to support the
belief that attitudes are difficult to measure and even more
so to change. Two areas of attitudinal change were
investigated in this thesis. The first area was toward
environmental concerns. The survey used to measure this was
constructed to be generic; that is, it would fit into almost
any environmental unit. it asked many questions that were
not covered in the unit under present consideration. Those
questions were considered for this thesis. The questions of
most immediate importance were those which dealt with local
rivers (See Appendix D). Given the amount of time spent at
the river and the abundance of interest shown by the
students, it was disappointing to find that their attitudes,
as measured by this survey, had changed very little. For
example, when asked to choose between “inhabited" and

I'uninhabited" as terms applied to the local river, six

52

students marked 'uninhabited“ on the post-test. Although no
clear data was available on the reading ability of these
students, it is possible that they did not understand

“uninhabited“ in the context in which it was used.

An oral attitude survey would be an interesting
undertaking in an effort to solve the problem with students
who have low reading abilities. However, the time needed to
interview each student in detail would be prohibitive. This
instructor will continue to use a written attitude
instrument, but one with extensive revisions. The intent is
to rewrite the questions of the survey to accomplish two
goals. 1) to a custom fit the survey to this particular
unit, to eliminate many of the current questions and add
more on rivers and water quality: 2) to change the wording
of the questions to accommodate the reading skills of low

ability students.

The second attitudinal area under investigation in this
thesis was student attitudes toward science in general.
There were a large number of questions dealing with science
methods on the survey. These were all analyzed together and
the results are shown in chapter 3 to be significant at the
.01 level, indicating that student attitudes had indeed
become more positive toward the use of scientific methods.

This is considered by this instructor to be quite important

53

in the context of the difficulty of changing attitudes to
any measurable degree. Perhaps the reason for success was
that students in this school district have had almost no
experience with science as a process. Science classes at
the middle school level are taught in a classroom with no
lab facilities at all. Therefore, students have had very
little experience with hands-on science investigations. The
river study came as a pleasant surprise to them, and they
really enjoyed conducting their own “real science“. Given
that situation, perhaps it is not surprising that students
marked choices more favorable toward scientific methods on
the post-test compared to the pretest. Of more interest to
this instructor would be the results of an attitude survey
of these students in their adult years. An important
question is: Are the attitude changes measured in this
thesis permanent or will they be obscured in the maturing
process of the students, most of whom will take no further

science classes?

Another form of attitudinal evaluation was used in the
exit interviews of twenty-four students, forty percent of
the class. The most striking result of these interviews is
that fifty percent of those interviewed chose the ecology
unit as the one they enjoyed the most. This is gratifying
to the teacher who spent so many long hours preparing this

unit. On the other hand if any teacher had the time and

54

patience to spend two full years in the preparation of a

unit, would the results be the same as in this case?

A second interesting observation based on the interview
results is that more of the C and D students most enjoyed
the ecology unit than did the A and B students. In a class
which is required of all students, those with lower ability
levels or lower motivation levels are at most risk. yet no
students failed this unit! This instructor had observed a
higher level of confidence on the part of these C and D
students as the year progressed. Perhaps it is important to
begin a course of this type with units that allow these
"at-risk'I students to experience success at the very start.
Perhaps it is by capturing their interest, as in the stream

study, that their overall success can be increased.

Another interesting revelation from the interviews is
that although a majority of the students enjoyed the ecology
unit more than any other, they did not choose it as the one
from which they had learned the most. To understand this
one must read the actual question asked, which stressed
learning of NEW material ("In which of the four units did
you learn the most THAT YOU DID NOT ALREADY KNOW?').
Students have had some instruction in ecological concepts in
middle school, but have learned almost nothing about

genetics or evolution. the two areas in which the students

55

indicated they had learned the most. One premise of this
thesis and the reason for beginning with the stream study
was that students are more familiar with ecological concepts
than with others in biology. The results of the interviews

indicate that this strategy was successful.

Students were asked in the exit interviews to choose
between having the stream study in the fall or in the
spring. Over ninety percent of them chose the fall. This
would indicate that students were aware of the good reasons

for beginning with the familiar material.

A final observation from the interviews is that the
students’ overwhelmingly prefer the unit approach (question
7). Only two students (both of whom received a D on this
unit) would have preferred to work strictly from the
text000k. The rest (almost ninety-two percent) were
comfortable with jumping around in the text to find material
that applied to the unit. They seemed to thrive on
wondering what their eccentric instructor would ask of them
next. In the interviews they left little doubt of their
negative feelings the “read the chapter-—answer the

questions“ mode of teaching.

S6

The conclusion of the data analysis and interview
evaluation is that the ecology unit was very successful in

teaching material and in preparing the students for

difficult concepts, as well as in making some attitude

changes.

FUTURE PLANS

For the first time in a twenty-three year teaching
career this instructor has a data base (reviewed in this

thesis) for making decisions regarding the sequence of units

in the introductory biology course. Instructors usually

make decisions on the basis of what the text offers or on

the basis of how she was taught. That is no longer the

rationale for curriculum design. The ecology unit will

continue to be the introduction for the reasons explained in

the preceding section. The labs and field work will be

expanded to allow more data to be collected on the river.

There are almost limitless possibilities for expanding
studies in this stream area in future years. One of the

most exciting of these is the chance to work with other

science teachers in other area schools in a collaborative

effort to gather data on streams in the watershed of the St

Joseph River .

57

The current biology textbook will be up for review at
the end of the 1991-92 school year. On the basis of the
effectiveness of an ecology unit as the underlying theme for

a biology course, the book that will be chosen will be the
newest edition of Biological science: An Ecological
Wm.

WORKS CITED

American Chemical Society. 1988. Chgmggm. Dubuque, Iowa:
Kendall Hunt Publishing Co.

Begon, Michael, John Harper. and Colin Townsend. 1986.
WWW.

Sunderland, Mass. Sinauer Associates, Inc.
Biological Science Curriculum Study (BSCS). 1987.

WWW
Version). Dubuque, Iowa: Kendall Hunt Publishing Co.

Hurd, Paul D. 1989. A new commitment to students. The
American Biology Teacher 14 (September): 341-345.

Stout, Becky. 1986. Evaluation in Michigan middle schools
of a science education curriculum based on ruffed
grouse management. Master’s thesis. Michigan State
University.

58

SELECTED BIBLIOGRAPHY

Arms, Karen and Pamela S. Camp. Blology, 2d ed. New York,
NY: Saunders College Publishing, 1982.

Campbell, Neil A. Blology, 2d ed. Redwood City, CA:
Benjamin/Cummings Publishing Co., Inc., 1990

Davies, Mark. 'Teaching Biology: Time To Evolve a New

Style“. Won. 19 (Winter
1985): 257-58.

Flannery, Maura C. ”Teaching Less Can Mean Better
Teaching“.
15 (May 1986): 504. 565-66.

Harper, G.H. ”Why Not Abolish Ecology?'. Jou;nol_o1
Blologlool_£ouoollon. 16 (Summer 1982): 123-127.

Hummer, Paul J. Albert Kaskel, James E. Kennedy, and
Raymond F. Oram. Laboratory Bloiogx:lnyert1gatlng
Llylng_Systomo. Columbus, Ohio: Charles E. Merrill
Publishing Co., 1976.

Hummer, Paul J., Albert Kaskel, James E. Kennedy, and
Raymond F. Oram. Erob1ng_Le1e1:.of_L1£e;;A_Laboratorz
Mongol. Columbus, Ohio: Charles E. Merrill Publishing
Co., 1976.

Jennings, Arthur. 'Biological Education: The End of the
Dinosaur Era?'.
17 Winter 1983): 298-302.

Kormandy, Edward J. and Bernice E. Essenfleld. Blolog1;_4A

Sistmes_fipproach;;Laberatorx_nanua1. Menlo Park Ca:
Addison- -Wesley Publishing Co. , Inc., 1988.

Miller, Kenneth R. and Joseph Levine. Blology. Englewood
Cliffs, NJ: Prentice Hall, 1991.

59

60

Mitchell, Mark K., and William B. Stapp. Eiolo Manual for
Wm. Dexter. Mich.=

Thomson-Shore Printers, 1986.

Otto, James H., Albert Towle, and W. David Otto. Blology
lnyoollootlono. New York: Holt, Rinehart and Winston,
Publishers, 1986.

Otto, James H., Albert Towle, and W. David Otto. Mooonn
Blolooy. New York: Holt, Rinehart and Winston,
Publishers, 1986.

APPENDIX A

STUDENT HANDOUTS

62

LIMITING FACTORS

If you examine the distribution of animals and plants
over the surface of the earth, it becomes obvious that no
species is found everywhere. Why? Some parts of the earth
are too hot, too cold, too dry, too wet for any one species
to survive. Biologists only became aware that each species
has its own special requirements for existence in the
1800’s. Liebig stated in 1840 that the rate of growth of
each population of organism is limited by whatever essential
nutrient is present in the shortest supply or minimal
amount. He had studied crops and found that the yield of
those crops was limited not by water and carbon dioxide.
which they need lots of and which are usually present in
large amounts, but by elements such as boron or manganese
which they need only in trace amounts. We now call Lieblg’s
law the LAW OF THE MINIMUM. The drawing (Figure 1)
illustrates this law. Regardless of how tall the rest of
the staves may be in the bucket, the shortest stave
determines the level of water in the bucket. So too, the
requirement that is in the shortest supply, the limiting
factor, governs the life of an individual organism or

population of organisms.

63

Today we recognize that Liebig was correct, but that
there are also cases in which it is the interaction of more
than one factor in the environment that causes the limit on
growth. In other words a high concentration of one factor
may effect the need for another. An example is that
Mollusks such as clams can substitute strontium for calcium
in making their shells if calcium is present only in small
amounts. That makes calcium less limiting than it would
normally be. Another example is that plants require less
zinc if they are grown in the shade than if they are grown
in the sun. Grasses use more water when the nitrogen in the

soil is low.

The types of interactions in the above paragraph
complicate the idea of the Law of the Minimum so that we
have now come to realize a wider concept-~the LAW OF
TOLERANCE. The basic idea is that the various factors in
the environment are tolerated by a given organism in a
range. We call this the range of tolerance. It may be a
narrower range at different stages of an organisms life.
Usually the range is narrowest or most restrictive during
the reproductive stages. Larvae or eggs are less tolerant

than adults.

64

One example of this difference in range of tolerance of
an organism is found in the case of the blue crab. This
crab normally is found in salt water, although the adults
can tolerate the lower salt levels of rivers and frequently
migrate up the rivers. But the larvae cannot tolerate the
low salt levels so permanent populations of blue crabs have

never become established in the fresher water of rivers.

Another example of the range of tolerance is the
repeated attempts to introduce ring-necked pheasants into
the southern states of the US. The adults survive quite
well, but the eggs are evidently killed by the daily high
temperatures. As a result the species has never become

established in the South.

Now we know that a population of a type of organism in
a given environment is limited mostly by those factors which
are at or approach the limits of its range of tolerance.
These factors are called LIMITING FACTORS. You must
understand that too much of any factor is just as limiting
as too little. Stop reading at this point and make a list
of things which you think could work as limiting factors for
many plants or animals. When you have listed as many as you

can, continue reading the next section.

65

SPECIFIC LIMITING FACTORS

1. Temperature.

You have only to think of how few animals and plants
live in the arctic to know how limiting temperature can be.
In general water environments change temperature less than
those on land, so the organisms which live in the water are
less well adapted to temperature fluctuations. They are
less tolerant or have narrower ranges of tolerance than
those which live on land. For example some types of
Antarctic fish have a tolerance range of -2 C to +2 C. Now
that’s a narrow range! Some bacteria have a range of
tolerance on the other end of the temperature scale. There
are bacterial colonies living and thriving in deep sea hot

springs at temperatures around 250 C!

Some organisms live at the extreme limits of their
range of tolerance by having evolved strategies for dealing
with the extreme temperature. For example, many animals
burrow into the soil or snow to escape the heat or cold.
This is effective for many burrowing animals in Alaska where
the surface temperature of the snow is often around -55 C,
but the temperature under the snow at the surface of the

soil is a much warmer -7 C. Other

66

strategies include being active only in the cooler desert
night, building thick layers of fat or fur as protection
from cold, or migrating to other areas during the winter.
These strategies are controlled by the animal’s inherited
genes, not by its own reasoning abilities. So we must think
of these as adaptations by the whole species, not by any

individual.

2. Light

Sunlight is, of course, the ultimate source of energy
for all ecosystems so it is one of the most important
factors involved in the distribution of plants and animals.
However, prolonged exposure to high intensities or short
wavelengths can kill cells, so that, as with every
environmental factor too much can be as damaging as too
little. If light is completely absent from an area, such as
in the deepest water or in caves, the community is limited
to animals, bacteria, and fungi. This type of community is
dependent on energy sources that come in from other areas
where plants can live and carry on photosynthesis.

One of the most interesting effects of light on
organisms is the PHOTOPERIOD, which is the number of hours
of daylight per day. It has an effect on the flowering of

plants, the migration of birds, the spawning of fish, and

67

the seasonal changes in color of some birds and mammals.
Some crops will not do well in a given area because the

photoperlod is outside their range of tolerance.

3. Water

Obviously water is a factor needed in various amounts
by all organisms. It is a limiting factor primarily for
land organisms. Most land organisms’ bodies consist
primarily of water. For example, humans are about 70% water
and pineapples are almost 90% water! Plants and animals
have developed various strategies to keep from losing
valuable water while living on land. Cactus have developed
needles instead of broad leaves, because this shape exposes
less of the leaf tissue to the air and decreases
evaporation. Cactus also have large amounts of water
storing tissues in their stems. Desert rats excrete their
urine in solid form to save the water normally used to
dilute it. Most land animals have thick, water-proof skin.
Earthworms, which have thin, moist skin that evaporates
water very quickly, survive by burrowing into the soil where
the humidity is much higher than in the air.

Water, like all other limiting factors, can be a
problem also when there is too much of it. Earthworms

cannot get oxygen from water, so when their burrows are

68

flooded by large rains they come to the surface. Plants

often die if their roots are completely flooded.

Water is such an important limiting factor that it is
used to define some land ecosystems as shown in the

following table:

WE ENYIRONMENI
0-10' Desert
10-30' Grassland
30-50" Dry forest
over 50' Wet forest
4. Oxygen

Oxygen is not usually limiting for land organisms,
except those living deep in the soil, on the tops of
mountains, or within other animals (like a tapeworm). But
it is a very important limiting factor in all AQUATIC
environments (those in water). The reason for this
difference is that oxygen is so much less soluble in water
than in air. The gills of a fish or clam will have to pump
26 gal of water to extract only 1 gram of oxygen. That is a
ratio of 100,000 to 1! The lungs of air breathers, in
contrast, only have to pump 1 gal of air to get 1 g of

oxygen. That is a ratio of

69

only 5 to 1. This has had an effect on the structure of
gills. The water flow in gills is in one direction: the
water does not turn around to flow back out. That is
because it costs energy to turn water or air around. We can
afford to do this in our lungs because we breathe air, but a

fish can not afford it in its gills.

It is very important that you understand that animals
which live in water do not use the oxygen atom that is part
of the H20 molecule. Instead they use only the free oxygen
(Oz) that is dissolved in the water. The sources of this
dissolved oxygen are mostly from the air where the water and
air meet and from the oxygen given off by water plants when
they are using sunlight to make food in the process of
photosynthesis. Do you see that the amount of dissolved

oxygen in water could depend on the amount of light?

5. Carbon dioxide

C02 is normally not a limiting factor except that it
can be in excess (too much) for fish and insect larva in
water ecosystems. It does have an effect on the pH of
water, which we will discuss later. The sources of C02 in
water are from the air where it meets the water, from
respiration by animals as they burn their food, from the
process of decay of dead organisms and their waste, and from

underground sources.

7O

6. pH

Remember from your study of physical science that pH is
the measure of how acidic or basic a water solution is. The
range of tolerance of most water organisms to pH is usually
quite broad, but some types of pollution can be a real
problem. The most famous example of this is ACID RAIN in
which certain gases from air pollution dissolve in the rain
water and increase the acidity of streams, soil, etc.
Carbon dioxide is one of the gases that dissolve in water to

give an acid. The equation for this 13:
C02 + H20 """ > H2C03

7. Water currents

In swiftly flowing streams the water current is
definitely a limiting factor as it will sweep away any
organisms that do not have strategies for dealing with it.
You will find in our study that animals which live in
fast-moving water are often very stream-lined in shape, have
strong swimming ability, or have devices for clinging to

rocks or plants.

8. Trace elements

Even though these are elements which organisms need in
only very tiny quantities, they are very often limiting
because they are found in small amounts in the environment.

For example parts of Australia are very low in copper and

71

cobalt and this causes disease in plants and animals. like
sheep. Other elements in this category are manganese, zinc,

iron, sulfur, selenium. boron.

9. Soil

The type of soil, the amount of topsoil, the soil’s pH,
water-holding capacity, etc. are often limiting factors for
plants. The ability of many animals to survive in a certain
environment depends on the presence of certain plants, so

soil is important indirectly to animals also.

10. Fire

It took a long time for us to understand that fire is a
necessary factor in some populations. An interesting
example of this is that the jack pine trees in Michigan have
cones that will not release their seeds unless they have
been exposed to the heat of fire. 50 when we controlled ALL
forest fires, we caused population of jack pines to decrease
enormously. The little bird, Kirtland’s warbler, nests only
in jack pine trees of a certain height. When we decreased

the number of jack pines, we inadvertently decreased the

72

nesting sites for this bird which is found only in Michigan
out of the entire US. The DNR now does CONTROLLED burning
of certain areas to allow jack pines to reproduce and the
number of Kirtland’s warblers is beginning to increase

again.

11. Pressure

This is a limiting factor in two areas on earth. See
if you can think of these two before reading on. One of
these areas is high in the mountains where air pressure is
low. This causes oxygen to pass slowly across the membranes
of the lungs into the blood. Animals which live in these
areas have special physiological strategies for dealing with
this lack of oxygen. Another area of the earth in which
pressure is a problem is in the deepest oceans. There are
some deep sea bacteria which can live only at pressures of

500 atmospheres!

73

FOOD WEB ASSIGNMENT

For each of the food webs below first draw a diagram
showing the producers on the bottom and the third level
consumers on the top. Place the decomposers a little to one
side as we did in class. The second thing you are to do is
to make a separate list of all the prOducers, decomposers,
first-, second-, third-level consumers in all the food
chains. If there are any organisms in these lists with
which you are not familiar, you must spend a little time in
the library looking them up.

i. Bacteria, Bird (small), Earthworm, Fox, Grass,
Grasshopper, Mountain lion, Mouse, Owl, Rabbit,
Raspberry bush, Shrew, Snake, Spider

2. Algae, Bird, Crab, Clam, Fish (small), Fish (large),
Human, Protozoa, Starfish, Worm (eats algae)

3. Aquatic plants, Grasshooper, Hawk, Heron, Land plants,
Mallard duck, Mouse, Owl, Rat, Sandpiper, Sparrow,
Smelt, Shrimp, Vole

Now make your own list and food web diagram of all the
organisms found in a temperate deciduous forest (if you do
not know what that is, look it up). Make sure NOT to
include man and make sure TO include predators which man has
destroyed as part of that environment. In other words make
the fooo web as it was before we interfered with it.

QUESTION: Why do you think the third level consumers are
usually shown on the top of the fooo web diagram? What does
this signify? Why doesn’t any other animal eat the animals
which are third-level consumers?

APPENDIX B

STUDENT LABORATORIES

75

LIMITING FACTORS FOR ALGAE

W

One of the purposes of this lab is to develop an
understanding of the scientific methoo and an appreciation
of its practical applications to everyday problem solving.

INTRODUCTION;

Phosphorus (P) and nitrogen (N) are necessary nutrients
for the growth of any plant life. The production of
carbohydrates, through photosynthesis, does not in itself
satisfy the needs of plant cells. Various fats and proteins
must be formed from carbohydrates to furnish the additional
components needed for life. Phosphorus and nitrogen enable
this to take place. But, if either of these nutrients is in
short supply, it becomes a limiting factor, retarding
further growth. This is Lieblg’s Law of the Minimum.

In this experiment you will be testing this law using a
solution of nutrient fertilizer in varying concentrations
and a suspension of algal cells from an aquarium. The
problem you will be dealing with is the amount of growth in
each concentration of fertilizer (containing both P and N).
You will be graphing your results.

HXRQIHESLS;

Write three or more hypotheses dealing with the
relationship between the growth of the population of algae
and the concentration of fertilizer. Choose the one which
you feel is the best.

MATERIALS;

Dropper

7 bottles

teaspoon

tablespoon

suspension of green aquarium scum
liquid plant fertilizer

distilled water

half-inch pieces of chalk

Spec 20 and cuvettes

76

W

1.

Be sure to mark the bottles and tubes accurately with
numbers 1--7 and DO NOT mix them up.

It will help if each week you will rotate the bottles so
that all sides are exposed to sunlight.

BROCHURE;

Set up 7 bottles each containing a piece of chalk and 10
drops of the aquarium scum. This scum is the source of
the algae colonies. Label each bottle with 1-7.

Fill the bottles according to the following chart:
BOTTLE AMT FERTILIZER AMT. H20

full none
5 tablespoons fill
1 tablespoon fill
1 teaspoon fill
20 drops fill
2 drops fill
none fill

\ImmwaH

Place a cover over each bottle and place them in the
sun.

At the end of each week swirl each bottle and withdraw
enough of the colony to fill a cuvette tube which is
marked with the same number as the bottle.

Using the Spec 20, measure the absorbance/ transmittance
of each tube and record in your data table. Use a
wavelength setting of 430.

Return the material from each tube to the bottle from
which it came. BE SURE NOT TO GET THE TUBES AND BOTTLES
MIXED UP.

At the end of five weeks graph the absorbance againSt
the time for each colony. Use a different color for
each colony (bottle).

77
W

Carefully analyze the data collected. Accept or reject
your chosen hypothesis on the basis of the class data. Be
sure to explain your accepting or rejecting the hypothesis
on the oasis of ooservable and tabulated data.

78

TEMPERATURE AS A FACTOR IN DETERMINING DISSOLVED OXYGEN

W

One of the purposes of this lab is to develop an
understanding of the scientific method and an appreciation
of its practical applications to everyday problem solving.

W

Water quality is essential to many forms of life other
than mankind. Land and aquatic organisms all depend on
water for survival. There are many ways to test for water
quality, just as there are many different kinds of water
systems to test, such as lakes, rivers, and streams. In
doing this laboratory exercise you will be performing a task
similar to those used by water researchers and scientists:
collecting data and interpreting the results.

You will be testing for the amount of dissolved oxygen,
abbreviated D.O. Dissolved oxygen is essential to the
metabolism of all aerobic aquatic organisms. Therefore, the
concentration of DO is a direct indicator of the
distribution, behavior, and growth of aquatic organisms.

The factors that control dissolved oxygen concentration
are important in determining oxygen availability to these
creatures. The rates of oxygen input (atmospheric,
photosynthetic, and wave action) are counterbalanced by
oxygen output (metabolism and respiration). The rate of
this oxygen use allows for the evaluation of the metabolism
of fresh water organisms.

The problem you will deal with in this lab is the
effect of water temperature on the concentration of
dissolved oxygen.

W

Write three or more hypotheses for the problem of the
relationship between temperature and concentration of
dissolved oxygen. Choose the one which you feel is the
best.

79

W

Ring stand

Ring

Wire gauze

Bunsen burner
Beaker tongs

1 beaker 400-500 ml
2 beakers 100 ml
Thermometer

DO Hach kit

W

Be sure to eliminate all air bubbles in bottles before
shaking.

Bottles must be thoroughly rinsed before continuing.

Keep PAO dropper vertical to maintain proper drop size.

W

1. Follow all steps according to the Hach kit manual for
each sample to determine DO. All readings will be taken
at 10 C intervals. The flocculent (woolly) precipitate
may be flushed down the sink with copious amounts of
water.

2. Remove 350 ml of the sample to be tested. Place the
thermometer in the beaker: wait one minute and record
the temperature. Re-read "Cautions and Pitfalls“. Now
take the concentration of dissolved oxygen. Record.
Rinse bottle thoroughly.

3. Heat the remaining sample on the ring stand until a
temperature increase of 10 C is achieved. Take the DO
concentration and record both temperature and DO. This
is trial 2.

4. Repeat step 3 until you have 6 readings. Be sure to
rinse bottle thoroughly between each step.

80

DATE;

Make a data table to include the temperature and
concentration of DD for each of the 6 trials.

Graph your results using temperature on the X axis
(horizontal) and DO concentration on the Y axis (vertical).

W

Carefully analyze the data collected. Accept or reject
your chosen hypothesis on the basis of the class data. Be
sure to explain your accepting or rejecting the hypotheses
on the basis of observable and tabulated data.

QUESTIONS;

1. Why is it important to be sure there are no air bubbles
in the sample bottle?

2. What is the purpose of rinsing the bottle thoroughly
before making more tests?

3. According to your data and graph, was there one 10 C
interval that had a much greater/smaller change than the
other 5? Suggest a reason for this.

4. By extrapolation of your graph, determine the
concentration of DO at the boiling point (100 C)

5. Suggest two other inorganic factors that may influence
the level of DO and discuss how they might effect the DO
content. (Hint: most inorganic factors are also in the
water.)

81
BIOLOGY LAB
pH OF COMMON SUBSTANCES

INTRODUCTION:

You have learned that pH is a scale measuring the
concentration of hydrogen ions in solutions. The scale is
from 0 to 14 with 7 being neutral. pH lower than 7 is
acidic and pH higher than 7 is alkaline or basic. In this
lab you will gain experience with various methods of
measuring pH by comparing pH of several household
substances.

PROCEDURE:

1. To use the large pH meter first make sure it is set on
STAND-BY. Remove the electrooe CAREFULLY from its holder
and rinse it with water from the wash bottle. The rinse
water should go into the waste beaker. GENTLY place the
electrooe into the solution to be tested. Turn the meter to
'pH MODE“ and read the pH to the nearest 0.1 on the top
scale. Turn the meter to STAND-BY, remove the electrode
from the solution, rinse it from the wash bottle, and
replace the electrode into its holder.

2. To use the portable pH meter remove the protective cover
and place the electrode in the solution to be tested. Turn
the meter on and read the pH to the nearest 0.1. Remove the
electrode from the solution, turn the meter off, and rinse
the electrode with water from the wash bottle.

3. To use the pH paper, dip a small strip of the general
paper into the solution to be tested and compare the color
to the chart on the side of the paper holder. Using this
approximate pH as a guide, choose a more specific paper and
repeat the procedure. BE VERY CAREFUL NOT TO ALLOW COLOR
CHARTS TO COME OUT OF THE HOLDERS. Replace all pH paper
holders into the tray.

4. Using the three methods above, measure the pH of as many
of the substances as you have time for. Be sure to use more
than one method in order to compare the readings. Make a
data table for reporting your results.

82

LABORATORY INVESTIGATION
ORGANISMS AND pH

W

One of the purposes of this lab is to develop an
understanding of the scientific method and an appreciation
of its practical applications to everyday problem solving.

INTRODUCTION;

In your reading assignment on limiting factors you
learned that pH is the measure of how acidic or basic a
water sample is. You also learned that pH can be limiting
to organisms, but often is not. In this lab we will deal
with the problem of how living tissue deals with changes in
pH. Often the changes in pH come about because of the
metabolic activities of the tissue itself, and so is
unavoidable. How do organisms survive and maintain
themselves in spite of metabolic activities that tend to
shift pH either toward acidic or basic ends of the pH scale?

W

pH meter or pH paper

tap water

small beakers

graduated cylinder
dropping pipets

0.1 N NaOH

0.1 N HCl

liver or potato homogenate
egg white--diluted

2% warm gelatin

sodium phosphate pH 7 buffer solution

W

Both HCl and NaOH are strong chemicals which are
harmful to your skin and to your clothes. Goggles and
aprons are ABSOLUTELY REQUIRED. Should you spill either
chemical on you begin rinsing with tap water immediately and
tell your teacher. Should you spill either chemical on the
lab table or floor, tell your teacher.

83

PART A

In order to compare the reaction of living substances
to that of nonliving materials in relation to pH changes,
you will first use tap water as the solution to be tested.
You will add progressively larger amounts of first HCl
(hydrochloric acid) and then NaOH (sodium hydroxide--a base)
to tap water and will measure the pH after each addition.

W

Write a hypothesis concerning the effect of HCl on the
pH of tap water.

Write a hypothesis concerning the effect of NaOH on the
pH of tap water.

PROCEDURE;

1. Prepare a data table with a section for the changing pH
after HCl additions and another section for the changing
pH after NaOH additions.

2. Pour 25 ml of tap water into a small beaker.
3. Record the initial pH of the tap water.

4. Add 0.1 N HCl a drop at a time, swirling CAREFULLY tomix
after each drop. Determine the pH after each 5 drops
have been added until 30 drops have been used. Record
the pH measurements in your table. Rinse the beaker
thoroughly.

5. Pour another 25 ml of tap water into the beaker and
record its initial pH.

6. Add 0.1 N NaOH drop by drop, recording the pH changes in
exactly the same way as for the 0.1 N HCl.

7. Make a simple graph, plotting 2 lines for the change of
pH in tap water against the drops of acid and base
solutions added. Use two colors, one for the acid and
one for the base.

CONCLUSIONS;

Carefully analyze the data table and graph you have
developed. Discuss the effect that acid/base had on the pH
of tap water. Accept or reject your hypothesis on the basis
of the data you have collected. Be sure to explain your
reason for accepting or rejecting the hypothesis.

84

PART B

In this part of the lab you will be doing the same

procedure as in Part A, except you will use samples from
living tissues--a tissue homogenate, egg white, and gelatin
instead of the tap water. A tissue homogenate is simply
plant or animal tissue chopped with a little water in a
blender. This separates the cells and releases the
chemicals which were inside the cells.

NYEQIHESIS;

Write a hypothesis concerning the relative amount of pH

change with HCl and NaOH between tap water and the tissues.
(Will the tissue homogenate change pH more or less than the
tap water did?)

BROCHURE;

1.

Prepare a data table similar to the one you used in Part
A. You will need a separate section for the tissue
homogenate, for the egg white, and for the gelatin.

Each will be measured with NaOH and with HCl.

2. Repeat the steps from Part A but use the tissues instead
of tap water.

3. Plot simple graphs, plotting 2 lines for the change of
pH in the tissues against the drops of acid/base
solutions added. Use 2 colors, one for the acid and one
for the base.

CONCLUSIONS;

Carefully analyze the data table and graph you have

developed. Compare them to those developed in Part A.
Accept or reject your hypothesis on the basis of the data
you have collected. Be sure to explain your reason for
accepting or rejecting the hypothesis.

85

PART C

What accounts for the behavior of living tissue in
response to changes in pH? Why aare the changed not as
great as when nonliving material, such as tap water was used
in the lab? Frequently in biology, it is difficult to study
living tissue. Investigators have found that they can learn
as much, and sometimes more, by substituting a model for the
real thing. We will use aa model to get data to help us
answer the questions asked at the beginning of this
paragraph.

PROCEDURE;
1. Prepare a data table similar to that used in part A.

2. Test the buffer solution (a nonliving chemical
solutions--a model) using the same techniques as used in
parts A and B. The only difference will be to
substitute the buffer solution for the tap water and the
'tissues. Record all your data.

3. Prepare a graph of the buffer solution in the same way
that you did the graphs for parts A and B. Use one
color for acid and one for base.

QUESTICNS;

1. Is the response of the nonliving buffer solution to
change in pH more like that of water or of the tissues?

2. How does the reaction of the buffer solution serve as a
model for the response of the biological materials
(Means)?

3. Would the presence of buffers in living cells aid or
hinder the response of that organism to changes in the
pH of the environment?

86

BIOLOGY LABORATORY
WATER QUALITY
TESTING FOR IONS

Background:

The water that we use on a daily basis is more than
just H20. Dissolved in it are various ions, atmospheric
gases and possibly a variety of other contaminants.
Contaminants such as mercury and lead compounds, pesticides,
and organic solvents exist in lakes and streams and in our
drinking water and are toxic to wildlife and to humans.
These contaminants are typically found at VERY low
concentrations in the part per million to part per billion
range and require sophisticated and expensive analytical
techniques to detect.

Ions are usually found at much higher concentrations in
the gram per liter or part per thousand range and are easy
to detect at these levels by using one-step chemical
reactions that form a visible result such as a precipitate
(settles to the bottom) or a color change. However, it must
be kept in mind that these tests can only confirm that an
ion is present. A negative test result (no color change or
no precipitate) does not necessarily indicate that the ion
is not present, since it may be present in such a small
amount that the color or precipitate cannot be seen.

Ions are not always considered contaminants in water,
for it is ions that give 'mineral' water its pleasing taste.
In our drinking water, ionic forms of chlorine prevent the
growth of bacteria that cause disease and fluoride ions help
prevent cavities by stopping the growth of bacteria that
form plaque on our teeth. Some ions, while harmless at low
concentrations, can cause problems at too high
concentrations. For example, high iron or sulfur ion
concentrations can lead to the growth of bacteria that make
drinking water taste bad..

Objective:
To test for the presence of iron, calcium, chloride,
and sulfate ions in water.

87

Procedure:

A. SET UP

1. Rinse 5 test tubes with distilled water.

2. Use a graduated cylinder to measure 2 ml of tap water
into a test tube: mark the level with a marker. Mark
the other four test tubes at the same level so that
further measuring is not necessary. Be very careful of
these marks. Label the test tubes in the following
manner:

R = reference solution
T a tap water

D = distilled water

N = Nottawa river water
M = Mill stream water

B. TEST FOR Tet3 IONS.

1. Pour 2 ml of iron nitrate solution into the test tube
labeled R.

2. Add 2 ml of distilled water to the tube labeled D.

3. Add 2 ml of river water to the tube labeled N.

4. Add 2 ml of mill stream water to the tube labeled M.

5. Add 2 ml of tap water to the tube labeled T.

6. Add three (3) drops of KSCN solution to each test tube,
mixing thoroughly.

7. Holding a sheet of white paper behind the test tubes.
look for a color change (usually red) in any of the test
tubes. Positive test will be in test tube R.

8. Discard solutions in the proper waste containers. Wash
test tubs with tap water and rinse them with distilled
water before going on to the next test.

0. TEST FOR Ca+2 IONS.

1. Add 2 ml of Calcium chloride solution to the test tube
labeled R.

2. Prepare the other four test tubes in the same manner as
in part B.

3.

Add three drops of HC H302 and three drops of Na2C204 to
each test tube. Mix Thoroughly

88

4. Observe each test tube carefully for any changes.
Positive test will be in test tube R.

5. Discard solutions in the proper waste containers. Wash
test tubes with tap water and rinse them with distilled
water before going on to the next test.

D. TEST FOR c1'1 IONS

1. Add 2 ml of Calcium chloride solutions to the tube
labeled R.

2. Prepare the other four test tubes in the same manner as
in part B.

3. Add three drops of AgNO3 to each test tube, mixing
thoroughly.

W

4. Observe each test tube carefully for any changes.
Positive test will be in test tube R.

5. Discard all solutions in proper waste containers. Wash
each test tube in tap water and rinse with distilled
water before going on to next test.

8. TEST FOR so;2 IONS.

1. Add 2 ml of iron sulfate solution to the tube labeled R.

2. Prepare the other four tubes in the same manner as in
part B.

3. Add three drops of BaClz solution to each tube and mix
thoroughly.

4. Observe each test tube carefully for any change.
Positive test result will be in tube R.

5. Discard all solutions in proper waste containers and
clean up entire lab area.

DATA:

Make a data table listing all waters tested, marking each
positive or negative for each ion.

Write a description of the positive test for each ion.

89

BIOLOGY LAB
INTRODUCTION TO MICROSCOPES

Part A. Becoming familiar with the microscope.

Label the parts of the microscope on the diagram.

Turn the objectives to low power. Notice a faint click
as it slides into place.

Look through the eyepiece. A circle of bright light
should now be seen.

Adjust the mirror and diaphragm to make the circle of
light as bright as possible.

Look at the SIDE of the microscope. Slowly turn the
coarse adjustment back and forth. Notice the movement
of the low power Objective.

Turn the fine adjustment. Notice the movement of the
low power objective. It may be difficult to see.

Part B. Preparation of a temporary wet mount slide.

1.

Remove a piece of hair from your head. We will use this
as an example specimen.

With your finger place a drop or two of water on the
center of the slide.

Place the hair (or any other specimen) in the water.
Place a cover slip over the drop of water. To avoid

trapping air under the cover slip, lower the cover slip
at an angle as demonstrated by your teacher.

Part C. Location of an object under the microscope.

1.

Be sure the microscope is on LOW POWER! LOW POWER IS
ALWAYS USED FIRST IN LOCATING OBJECTS! Adjust the
mirror and diaphragm for best light.

Place the wet mount of a hair on the stage of your
microscope. Position the slide so the hair is directly
over the center of the stage opening. Secure the slide
in place with the clips.

90

Look to the side of the microscope. Slowly lower the
low power objective by turning the coarse adjustment
wheel until the objective almost touches the slide. On
our microscopes that means lowering it as far as it will

90.

Look through the eyepiece. Turn the coarse adjustment
so the objective rises from the stage. The hair should
become visible within the first turn and a half of the
adjustment. If it does not, move the slide around to
center the hair under the objective.

Bring the hair into sharp focus by turning the fine
adjustment.

Failure to see the specimen may be due to one of the
following:

a. Hair not centered over the stage opening.

b. Objective raised too far.

c. Not properly focused

d. Improper lighting.

e. Low power objective not clicked into place.

Part D. Increasing the magnification.

Locate the hair on LOW POWER as in PART C.

Turn the nosepiece until the high power objective clicks
into position. Do NOT move the coarse adjustment knob.
If the microscope is properly focused on low power, the
high power objective will NOT hit the slide. If it
does, do not force it: call your teacher.

Look through the eyepiece. The hair should be visible.
However, it may need to be focused. USE THE FINE
ADJUSTMENT ONLY. NEVER USE THE COARSE ADJUSTMENT WITH
HIGH POWER!

Adjust the diaphragm if needed for best lighting.

Failure to see the specimen may be due to reasons listed
above.

91

Part E. Position of objects when viewed under the

microscope.

Cut a lower case "e” from a ditto.

Prepare a wet mount slide of the 'e'. Place it on the
stage and position the slide so that the “e” faces you
as it would on a newspaper page.

Use low power and focus on the "e“.

While looking through the eyepiece, move the slide
slowly from left to right.

While locking through the eyepiece, move the slide
slowly from right to left.

While looking through the eyepiece, move the slide
slowly away from you.

While looking through the eyepiece, move the slide
slowly toward you.

Part F. Use of the diaphragm.

1.

Prepare a wet mount slide of a few strands of absorbant
cotton.

Observe the cotton under low power. While looking
through the eyepiece, change the amount of light
entering the microscope by adjusting the diaphragm.

Observe the cotton under high power. Again change the
diaphragm from maximum to minimum light and back again.

Part G. Depth of field.

1.

Prepare a wet mount slide of two threads of different
colors. Cross the two strands to form an X before
adding water and the cover slip.

Locate the strands under low power. Center the slide at
the point where the strands cross. Adjust the
diaphragm.

Change to high power and observe both strands where they
cross. Turn the fine adjustment back and forth by a
quarter of a turn while looking at the strands. This
should allow you to see first one and then the other in
proper focus.

92
INTRODUCTION TO MICROSCOPES
ANALYSIS

Write the functions for the following microscope parts:
1. Diaphragm

2. Stage opening.

3. Mirror or lamp.

4. Eyepiece.

5. Low power objective.

6. High power objective.

7. Revolving nosepiece.

8. Coarse adjustment.

9. Fine adjustment.

10. Stage.

11. Stage clips.

12. Total magnification is determined by adding the
eyepiece lens magnification to the objective lens

magnification.

13. An object should always be located first with low
power. TE

14. Which adjustment is used to sharpen focus with high
power?

15. A microscope should be carried with both hands,
upright, and close to the body. TF

16. What part of the microscope controls the amount of
light through the opening?

17. What is the total magnification of our low power lens?

18. What is the total magnification of our high power lens?

19. What is the total magnification obtained when using low
power with our eyepieces?

20. What is the total magnification obtained when using

high power with our eyepieces?

21.

22.

23.

24.

25.

93
Which adjustment is used to locate an object under low
power?
Which adjustment is used when focusing with high power?
The objectives should never be lowered toward the stage
with the coarse adjustment without looking at the

microscope from the side. TF

What was the position of the “e' viewed with the
microscope compared to its position on the slide?

What is the effect of the lenses of the microscope on
the movement of the “e'?

How could you position an object under the microscope
so it is viewed right side up?

27. Using low power, under what diaphragm setting are the

cotton fibers sharpest? (maximum, medium, minimum
light)

28. Using high power, under what diaphragm setting are the

29.

30.

31.

32.

cotton fibers sharpest? (maximum, medium, minimum
light)

Can you see both threads fairly clearly at the same
time when using low power?

Can you see both threads fairly clearly at the same
time when using high power?

Which has greater depth of field--high or low power?

State the relationship between increasing magnification
and increasing depth of field.

94

ANALYSIS OF FEEDING GROUPS
STREAM MACROINVERTEBRATES

TAKEN FROM
CUMMINS AND WILZBACH

The objective of this exercise is to do a quick initial
assessment of the food base of a stream ecosystem by
focusing on the roles played by the macroinvertebrates
present. Macro means larger than microscopic and
invertebrates are those animals without backbones.
According to the authors of the original lab, about 80-90%
of the organisms that you will find can be classified
accurately this way. This is good enough for our purposes,
but for a more detailed study, we would need to use more
complex keys.

Stream macroinvertebrates are separated into four
FEEDING GROUPS. SHREDDERS are dependent on large pieces of
organic matter such as leaves, needles, wood, and other
plant parts. COLLECTORS use small particles of organic
matter (generally less than 1 mm in size), either by
filtering from the passing water or gathering from deposits
in the sediments on the stream bottom. SCRAEERS are adapted
for removing attached algae, especially where it grows on
rocks or log surfaces in the current. EREDAQIRS are adpated
through behavior and specialized body parts for the capture
of prey.

We will take handfuls of organic materials from four
areas of the stream as follows:

a. Coarse Particulate Organic Matter (CPOM) = litter
accumulations of leaves, needles, bark, twigs, other
plant parts, and coarse fragments of these materials
from a riffle.

b. Fine Particulate Organic Matter (FPOM) = particles less
than 1 mm in size from the fine organic-rich sediment of
a pool.

c. Periphyton = Predominantly attached algae (diatoms) on
rock and wood surfaces.

d. Large Wood = Branches and logs. Taken from soft punky
wood fallen into the streams.

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FIRST LEVEL OF RESOLUTION
LARVAE iN PORTABLE CASE
Czdciisfljes (Order Trichopteral

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FIRST LEVEL OF RESOLUTION

LARVAE WITH FIXED RETREAT
AND CAPTURE NET
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FIRST LEVEL OF RESOLUTION
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101

BIOLOGY LAB
CRAYFISH

Section A--PRESERVED CRAYFISH

1. Observe the specimen. Does it have an endo- or an
exo-skeleton?

The body of the crayfish is divided into two distinct
regions. The region toward the head (anterior) is called
the CEPHALOTHORAX. It is the combination of the head and
the thorax common to all arthropods. The region away from
the head (posterior) is called the ABDOMEN. The abdomen
ends in a reduced segment called the TELSON.

2. How many segments are there on the abdomen?

3. The cepahlothorax is covered by the CARAPACE. How many
pieces make up the carapace?

Notice that a groove marks the division between the head and
thorax. Observe that the carapce extends forward. This
forms a horny beak called the ROSTRUM.

4. Where are the large compound eyes in relation to the
rostrum?

The most anterior appendages are the branched ANTENNULES.
Locate the antennae which are attached to the head,
posterior to the antennules.

5. What is the structure of the antennae?

Turn the crayfish over so that you can see its mouthparts.
Use a probe to move the mouthparts.

6. Do the mouthparts move up and down or side to side?

The thorax has eight pairs of appendages. Three pairs are
MAXILLIPEDS and are used in handling food. Five pairs are
legs. Try to find all eight pairs.

7. How are the maxillipeds different from the legs?

8. The first pair of legs are well-developed pincers called
CHELIPEDS. Are these the same size? If not, explain why
this might be so.

9. The next four pairs of legs are called WALKING LEGS. In
what ways do they differ from one another?

102

The abdominal appendages of the crayfish are called
SWIMMERETS. In the female, the first pair of swimmerets are
small. In the male, the first two pairs are modified for
transferring sperm.

10. Can you determine the sex of your specimen?

The sixth pair of swimmerets are enlarged to form the
UROPODS. The uropods and the tlson form the powerful tail
fin used in backward swimming. Find the ANAL OPENING on the
ventral (belly) side of the telson.

Section B--LIVING CRAYFISH

1. Observe a living crayfish for 5 minutes. Record any
behavior that you see.

2. Describe the manner in which the crayfish walks.

3. Gently touch a probe to an antennae. Describe the
reaction.

4. Shine a penlight flashlight on the anterior end of the
crayfish. Then, shine it on the posterior end of the
animal. Compare the reactions and explain this behavior.

5. Put 5 drops of saturated salt solution in the water near
the animsl. Describe the crayfish’s reaction.

6. Put 5 drops of vinegar near the animsl. Describe its
response.

7. Change the water in the bowl and add a drop of India ink
Just posterior to the cephalothorax. What is the direction
of the flow of water through the gill chambers?

8. What creates these water currents?

103

Part C--SUMMARY:

Give the function of the following structures of the
crayfish.

1. Antenna

2. Mandible

3. Maxilla

4. Maxilliped

 

S. First walking leg--Cheliped
6. Walking legs

7. First swimmerets

8. Swimmerets

9. Uropods/Telson

104

ARTHROPODS
CRAYFISH/INSECT COMPARISON

The handout for this lab is available in the following
published lab book:

Hummer, Paul J. , Albert Kaskel, James E. Kennedy, and

Raymond F Oram Waxing
LiyingLfiystgms. Columbus, Ohio: Charles E. Merrill
Publishing Co., 1976.

OBSERVATION 0F ALGAE AND PROTOZOANS

No handout is necessary for this lab. Simply use
dichotomous keys available for these organisms.

105

SCHOOLING BEHAVIOR IN FISH

WHEEL;

One of the purposes of this lab is to develop an
understanding of the scientific method and an appreciation
of its practical applications to everyday problem solving.

1W

Animals may gather in a group for different reasons.
If they are attracted to the same spot by the presence of
food, light, or some external stimulus, the group is called
the aggnggatg. If, however, they form a group because they
are mutually attracted to one another, the group is called a
school in the case of fish, and a hand, or flock, in the
case of mammals or birds. In fish, vision, swimming
movements in the water, and olfaction (sense of smell) may
all contribute to keeping the members of the schools
together, but vision is the most important cue. Schooling
fish seem to be attracted to each other mainly by their
appearance, and the attraction is the strongest for other
members of the same species. Schooling is a form of
communication between members of the same species, but fish
of different species do sometimes school together as well.

Schooling is very prevalent among all sorts of fish,
from very primitive ones to more advanced species. The
members of the school may be better protected from predators
than single fish, and they seem to be able to swim more
efficiently. A predator in a school has a greater chance of
locating food than does a lone predator. For
plankton-feeding fish, however, food is always present, and
there will be less food for each fish in a school than there
would be for a single fish. Members of a school can learn
from each other more quickly than a single fish can learn,
and they do not have to spend energy locating mates for
reproduction.

However, one big disadvantage of schooling behavior is
that it has made the human fishing industry very successful
and efficient and may ultimately lead to the decline or even
extinction of many fish species.

In this experiment you will be testing the role of the
visual component in schooling behavior. Because the fish
will be separated by a glass barrier, there can be no
communication by sound or chemical signals. In many fish
vision is the prime factor in the attraction of schooling

106

fish toward each other, but olfaction and sound seem to help
maintain the cohesion of an established school. In this lab
the problem you will be dealing with specifically is whether
brightly marked fish depend more on vision for their
schooling cues than do unmarked fish.

HYPOTHESIS:

Write three or more hypotheses dealing with the
relationship between dependence on vision and markings on
fish. Choose the one which you feel is the best.

W

2 large aquaria per group

4 large beakers per group

10 fish with markings

10 fish without markings
cheesecloth--enough to cover 4 beakers
large rubber bands

W

BEHAVIOR EXPERIMENTS WILL NOT WORK UNLESS THE ANIMALS
ARE TREATED WITH CARE AND PATIENCE.

DO:
1. Always use a net to transfer the fish.

2. Allow time for the fish to adjust to new conditions
before beginning your observations.

3. Wash and rinse your hands before reaching into the
experimental tanks to place beakers.

4. Treat fish with care.
5. Report any sick-looking or dead fish to the instructor.

6. Return all fish to the proper tanks when you are
finished.

107

DON’T:

1.

Disturb the fish more than necessary for the
experiments.

2. Expect the fish to respond instantaneously to a new
stimulus.

3. Reach into the stock tanks where the fish are kept.

4. Leave the fish in the experimental apparatus or tanks.

BROCHURE;

Part 1

Work with a partner and try these tests of schooling

behavior. The experimental set-ups are shown in Figure 1
and Figure 2.

Test 1 (Figure 1)

1.

Place several fish with markings in a beaker. Cover the
beaker with cheesecloth, secure with a rubber band, and
immerse the entire beaker slowly in the aquarium. Place
it into position on side A of the aquarium.

Place an empty beaker on side B to serve as a control.

Place a single test fish of the same species in the
tank.

Use a stopwatch to time the number of seconds spent by
the test fish in each half of the tank during a 5 minute

period (300 seconds). Record the results on your data
sheet.

Calculate the percentage of time the test fish spent on
side A and on side B.

Question: Did the fish spend more time on side A or side B?

Test 2 (Figure 1)

1.

Place two fish in the beaker and repeat the experiment
using aa different single test fish of the same species.
Record the results.

Calculate the percentage of the test period that the
fish spent on each side of the tank.

108

If you have time, repeat the test using different
numbers of fish in the beaker and using a different test
fish each time.

3. Calculate the percentage of the test period that the
fish spent with the school and the percentage that it
spent alone.

Question: Did the number of fish in the school affect the
tendency of the single test fish to spend time with the
school?

Test 3 (Figure 2)

1. Place 3 fish with markings in a beaker on side A of the
aquarium and 3 fish of another species without markings
in a beaker on side B. Be sure to put the same number
of fish in each beaker.

2. Place a single test fish with markings in the center of
the aquarium.

3. Use a stopwatch to time how many seconds in a 5 minute
period the test fish spends with its own species
(section A), with the other species (section B), and
alone (section C).

4. Calculate the percentage of time that the test fish
spent in each section of the tank.

Question: In which of the 3 sections did the fish spend the
most time?

Is there a big difference in the percentaage of time spent
with the two species?

Part 2 Visual markings may help fish to identify other
members of the same species, but not all schooling fish have
prominent markings. Test the schooling tendency of fish
without prominent markings in the following experiments and
compare your results to those you obtained for the fish with
markings.

Test 4 (Figure 1)

1. Place several fish without markings in a beaker on side
A of the aquarium, an empty beaker on side B, and a
single test fish of the same species free in the
aquarium.

109

2. Use a stopwatch to time the number of seconds spent in
each half of the aquarium during the 5 minute period.
Record the results.

3. Calculate the percentage of time the test fish spent on
side A and on side B.

Question: On which side did the test fish spend more time?

Test 5 (Figure 1)

1. Place 2 fish in the beaker, and repeat the experiments
using a different fish of the same species. Record the
results.

2. Calculate the percentage of the test period that the
fish spent on each side.

If you have time, repeat the test using a different
number of fish in the beaker and using a different single
fish each time.

3. Calculate the percentage of time the fish spent with the
school and alone for each test.

Question: Did the number of fish in the school effect the
tendency of the single test fish to swim with the school?

Test 6 (Figure 2)

1. Place 3 fish with markings in a beaker on side A of the
aquarium and 3 fish without markings on side B. Be sure
to put the same number of fish in each beaker.

2. Place a single test fish without markings in the center
of the tank.

3. Use a stopwatch to time how many seconds in a 5 minute
period the test fish spends with its own species
(section B), with the other species (section A), and
alone (section C). Record your results.

4. Calculate the percentage of time that the test fish
spent in each section of the tank.

110

Question:
In which of the 3 sections did the fish spend the most time?

Is there a big difference in the percentage of time spent
with each of the 2 species?

Was the test fish more attracted to visual markings or to
members of its own species?

RETURN ALL FISH TO THE PROPER TANKS WHEN YOU ARE FINISHED.

DAIA;

Construct a data table to record all six tests.
Include time spent in zones A, B, and C and the percent time
spent in zones A, B, and C.

W

Carefully analyze the data collected. Accept or reJect
your chosen hypothesis on the basis of the class data. Be
sure to explain your accepting or rejecting the hypotheses
on the basis of observable and tabulated data.

 

111

KEY: 3: test fish
marked fish
3: unmarked fish

School of Fish Empty Beaker (Control)

 

 

 

 

test fish

0

 

A B

Figure One: Schooling Behavior. In the aquarium setup for
testing with one school, a beaker with fish is placed an
side A and an empty beaker on side B to serve as an control.
The test fish is free to swim throughout the aquarium

 

 

 

 

School with School without

markings test fish markings
I l l I I I
I I l I l I
I I I l I I
I I I I I I
I I I I I I
l I I I I I I I
I I & I I I I # I l
I I & I I s l I # I l
I I& I I I I t I I
I I I I I l I I
l I l I

A C B

Figure Two: Schooling behavior. When two schools are used,
the aquarium is divided into three parts. A school of one
species is placed on side A and a school of another species
on side B. The free test fish can choose school A, school
B, or neither school.

APPENDIX C

STUDENT TESTS

113

BIOLOGY PRETEST
AQUATIC ECOSYSTEMS

1. Which would contain more dissolved oxygen?
A. Fast-flowing brook C. Pond
B. Slow-moving stream D. Lake

2. Which would contain more floating microorganisms or
insect larva?
A. Stream B. Pond

3. What is the ultimate source of energy for all the living
things in any environment?
A. Food C. Heat
B. Light D. Electricity

4. Which of the following would most limit the growth or
numbers of organisms that live in water?
A. Oxygen C. Pressure
B. Light D. Temperature changes

5. At each successive level of a food chain the amount of
energy available from food
A. Increases B. Decreases

6. What type of organism produces oxygen?
A. Bacteria C. Plant
B. Animal D. Fungus
B. All of those

7. The most common oxygen procucing process in living

things is
A. Respiration C. Photosynthesis
B. Digestion D. Fermentation

8. The most common carbon dioxide producing process in
living things is
A. Respiration C. Photosynthesis
B. Digestion D. Fermentation

9. What type of organism produces carbon dioxide?
A. Bacteria C. Plant
8. Animal D. Fungus
E. All of those

10. Would a poisonous compound, such as mercury, be more
concentrated in a pike or in a tadpole?
A. Pike B. Tadpole

11.

12.

13.

14.

16.

17.

18.

19.

20.

21.

114

If a large amount of manure is dumped into a small
lake, what will happen to the amount of dissolved
oxygen available in the water?

A. Will increase B. Will decrease

Decomposers cause things to rot. Are they beneficial
or harmful to the environment?
A. Beneficial B. Harmful

Which of the following often act as decomposers?

A. Bacteria E. A, C, and D

B. Plant F. A and D

C. Animal G. B and C

D. Fungus

Which would be an example of a first level consumer?
A. horse C. Oak tree

B. Eagle D. Bacteria

Which would be an example of a second level consumer?
A. Horse C. Oak tree
B. Eagle D. Bacteria

Which of the following would be a producer in a pond?
A. Bass C. Algae
B. Crayfish D. Bacteria

What are the maJor prooucers for a small, spring-fed
brook, about 2 feet wide?

A. Algae C. Moss

B. Trees around it D. Duck weed

Is the total mass of consumers in an environment
greater or less than the total mass of pr0ducers?
A. Greater B. Less

Choose whichever of the following would be important
factor(s) affecting the pH of a stream 3 water.

A. Acid rain

B. Type of bottome to the stream

C. Type of animals found in stream

D. Type of plants along the bank

Which would you expect to find in water that is low in
oxygen?

A. Trout C. Carp

B. Perch D. Snails

Which would you expect to find in water that is high in
oxygen?

A. Trout C. Carp

B. Perch D. Snails

22.

23.

24.

25.

26.

115

Which would you expect to be most affected by the
amount of calcium in water?

A. Carp C. Clam

B. Frog 0. Algae

Would there be most dissolved oxygen in cold or warm
water?
A. More B. Less

Fish breathe

A. Water

B. The oxygen in the water molecule

C. The oxygen dissolved in the water from the air

If a perch eats an insect, what per cent of the energy
from the insect’s body actually becomes stored in the
perch’s booy (for a larger fish to eat)?

A. 90% B. 10% C. 50% D. 25% E. 100%

E. coli is a type of bacteria. Why is it important?

A It causes diseases like colitis.

B. It is an indicator of the presence of human sewage
C it is a common decomposer in streams

D it proouces oxygen

116

BIOLOGY TEST
ECOLOGY I

Multiple Choice: Place the letter of the best answer in the
blanks.

1.

What is the effect of making smokestacks taller?
A. Cuts down on pollution in lower atmosphere.
B. Spreads pollution over a greater area.

C. Changes dangerous gases into harmless ones.
D. All of those

What elements in smog are largely responsible for making
rain acid?

A. Ca and C C. Cl and O

B. O and N D. S and N

A lake dead because of acid looks
A. Scummy and polluted

B. Clear and blue

C. Green and foamy

D. Clear and green

Which would be more vulnerable to acid rain?
A. Lakes with granite rock bottoms.
B. Lakes with limestone rock bottoms.
C. Lakes with mud bottoms.
D. All of those are equally vulnerable.
Large fish are killed by acid rain in what way?
A. By pH going up. C. By starvation
B. By pH going down. D. By DO going down

How could increasing acid make drinking water dangerous

to humans?

A. Leeches heavy metals like aluminum or mercury out
of rocks.

B. Dissolves copper pipes.

C. Creates too much acid in our stomachs.

D Kills fish and dead fish lead to pollution.

What substance is dumped into lakes to reduce acidity
temporarily?

A. Sulfur C. Dirt

B. Granite D. Limestone

If rivers are not acidic at all times, they are most
likely to be so in what season?

A. Fall C. Summer

B. Spring D. Winter

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

117

What stage of insect life cycle is most important to
food chains in streams?

A. Egg C. Pupa

B. Larva D Adult

What do most crabs eat?

A. Little fish C. Dead animals
B. Clams D. Plants

Besides food, what would be the most important limiting
factor in a mountain stream?

A. Light C. Oxygen

B. Water currents 0. pH

Animals which live in a fast-moving stream are often
A. Flattened C. Long and skinny
B. Round D. Square

What is one limiting factor that is almost always
important for all animals in ALL environments?

A. Food C. Light E. Water

B. Oxygen D. pH

How is fire a limiting factor for Jack pines?
A. Warblers only nest in certain size trees.
B. Fire destroys the seeds.

C. Fire opens the cones.

D. All of those

Why might a mountain stream have more oxygen than the
Kalamazoo River?

It is smaller

It has more algae

It is faster moving

It has more animals

All of those

WUOCDZD'

What is the advantage of the thin, flat shape of most
leaves?

A. Catch more water C. Catch more light
B. Keep H20 from evaporating D. All of those

Most photosynthesis occurs in what plant part?
A. Root B. Stem C. Leaf D. Flower

90% of all photosynthesis on earth happens in plants
which live where?

A. On land C. In forests

B. In water D. In fields

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

118

What animal process uses up the most energy?
A. Movement C. Communication
B. Digestion D. Fooo-getting

The form of nitrogen most common in the air is
A. Nitrate C. N2
B. Ammonia D. Nitrite

The organisms which “fix" nitrogen into forms which
organisms can use are

A. Legumes C. Soy beans

B. Bacteria D. Plants

What happened to the amount of nitrogen when trees were
logged off in a given area?

A. Increased in fields

B. Increased in streams

C. No affect unless trees were burned

Grasses need more water when

A. Nitrogen in soil in low

B. Zinc in soil is low

C. Strontium is substituted for calcium

Plants need less zinc if

A. They are high in calcium
B. They are in the shade

C. They have lots of water

What part of an animal’s life cycle if likely to be
east tolerant to limiting factors?
A. Larva B. Adult C. All are equal

Which type of organism would be least tolerant to
changes in temperature?

A. Land organisms C. Plants

B. Water organisms 0. Animals

The biomass at each successive level of a food chain
must
A. Increase B. Decrease C. Stay the same

Which would contain more dissolved oxygen?
A. Fast-flowing br00k C. Pond
B. Slow-moving stream D. Lake

Which would contain more floating microorganisms or
insect larva?
A. Stream B. Pond

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

119

What is the ultimate source of energy for all the
living things in any environment?

A. Food C. Heat

B. Light D. Electricity

Which of the following would most limit the growth or
numbers of organisms that live in water?

A. Oxygen C. Pressure

B. Light 0. Temperature changes

At each successive level of a food chain the amount of
energy available from food
A. Increases B. Decreases

What type of organism produces oxygen?

A. Bacteria D. Fungus
B. Animal E. All of those
C. Plant

The most common oxygen-producing process in living
things is

A. Respiration C. Photosynthesis
B. Digestion D. Fermentation

The most common carbon dioxide-producing process in
living things

A. Respiration C. Photosynthesis

B. Digestion D. Fermentation

What type of organism produces carbon dioxide?

A. Bacteria D. Fungus
B. Animal E. All of those
C. Plant

Would a poisonous compound, such as mercury, be more
concentrated in a pike or in a tadpole?
A. Pike B. Tadpole

Decomposers cause things to rot. Are they beneficial
or harmful to the environment?
A. Beneficial B. Harmful

Which of the following often act as decomposers?

A. Bacteria E. A, C, and D
B. Plant F. A and D

C. Animal G. B and C

D. Fungus

Which would be an example for a first level consumer?
A. Horse C. Oak tree
B. Eagle D. Bacteria

41.

42.

43.

44.

45.

46.

47.

48.

120

Which would be an example of a second level consumer?
A. Horse C. Oak tree
B. Eagle D. Bacteria

Which of the following would be a producer in a pond?
A. Bass C. Algae
B. Crayfish D. Bacteria

What are the maJor producers in a small, spring-fed
brook, about 2 feet wide?

A. Algae C. Moss

B. Trees around it D. Duck weed

Is the total mass of consumers in an environment
greater or less than the total mass of producers?
A. Greater B. less

Choose whichever of the following would be important
factor(s) affecting the pH of a stream’s water.

A. Acid rain

B. Type of bottom to the stream

C. Type of animals found in stream

D. Type of plants along the bank

Would there be more dissolved oxygen in cold or warm
water?
A. Cold B. Warm

Fish breathe

A. Water

B. The oxygen in the water molecule

C. The oxygen dissolved in water from the air

If a perch eats an insect, what per cent of the energy
from the insect’s body actually becomes stored in the
perch’s body (for a larger fish to eat)?

A. 90% B. 10% C. 50% D. 25% E. 100%

121

Matching: Place the letter of the best answer from the list

49.
50.
51.
52.
53.
54.

55.

56.
57.
58.
59.
60.
61.

62.
63.

at the right in the blanks at the left.

Any condition which approaches . Aquatic
or exceeds limits of tolerance Biomass
Process of converting light . Chlorophyll
energy into food energy . Consumer
Process of breaking down food Decomposer
and releasing stored energy Environment
Molecule which traps light energy . Food chain

Law of Minimum
Limiting Factor

Rate of growth of each organism
is limited by whatever essential

OZZFNQHEQWMDOW)

nutrient is in shortest supply Marine
Organism which converts light pH

energy into food energy . Photosynthesis
Organism which recycles atoms Predator

from living things DaCK to Producer

soil or air . Respiration

Organism which gets energy by

digesting body materials of other organisms.

Living and nonliving surrounding of an organism.

Flow or passage of energy through an ecosystem.
Organism which preys on other LIVING organisms for
food.

Pertaining to water or to those organisms which live in
water.

Pertaining to salt water or to those organisms which
live in salt water.

Scale used to indicate the acidity of a water solution.
Weight of all of one type of organism in an
environment.

True-False: Place + in the blank if the statement is true;
0 if the statement is false.

64.

65.
66.
67.
68.
69.

Too much of an environmental factor can be as limiting
as too little.

Plants produce carbon dioxide.

Plants produce oxygen.

Animals produce carbon dioxide.

Animals proouce oxygen.

The short cycle of carbon usually involves respiration
and photosynthesis.

Short Answer:

70.

71.

In our stream water, we measured D0. What does this
stand for?

All food chains must begin with what type of organism?

73.

74.

76.

77.

78.

79.

80.

81.

82.

83.

84.

85.

86.

87.

122
Name four elements which are needed in large amounts by
living things.

Name two elements which are needed in large amounts by
living things which are often limiting factors.

Name four elements which are needed in small amounts by
living things.

In what type of environment would pressure be a
limiting factor?

In what type of environment would oxygen most likely be
a limiting factor?

Name two uses for fooo in living things.

Compare the amount of energy which land and water
organisms must use in order to get oxygen.

Why is nitrogen often a limiting factor for plants when
the air is 78% nitrogen?

Give an example of a SLOW cycle of carbon into and out
of organisms.

Choose an appropriate type of atom and describe how it
cycles from atmosphere to organisms and back again.

Explain why any food chain can only go for a limited
number of steps.

What does it mean to say that an animal is at the “top
of the food chain“?

Name an animal that would be a first level consumer.
Explain why you chose that animal.

List the steps in an example food chain in a lake.
List the steps in an example food chain in a forest.

Using the diagram below, relate the staves (boards) in
the bucket of water to the Law of the Minimum.

123
BIOLOGY TEST
ECOLOGY II

Multiple Choice: Place the letter of the best answer in the
blanks.

1. Which would you expect to find in water that is low in

oxygen?
A. Trout C. Carp
B. Perch D. Snails

2. Which would you expect to find in water that is very
high in oxygen?
A. Trout C. Carp
B. Perch D. Snails

3. Which would you expect to be most affected by the amount
of calcium in water?

A. Carp C. Clam
B. Frog D. Algae
4. Which animal is a mollusx in the class Gastropoda?
A. Mayfly C. Snail
B. Clam D. Shrimp
5. Which animal is a mollusk in the class Pelecypoda?
A. Mayfly C. Snail
B. Clam D. Shrimp
6. Which animal is an arthropod in the class Crustacea?
A. Mayfly C. Snail
B. Clam D. Shrimp
7. To which phylum does a crayfish belong?
A. Arhtropooa C. Chordata
B. Mollusca D. Annelida

8. To which phylum does a leech belong?
A. ArthrOpoda C. Chordata
B. Mollusca D. Annelida

9. To which phylum does a trout belong?
A. Arthropoda C. Chordata
B. Mollusca D. Annelida

10. To which phylum does a mayfly belong?
A. Arthropoda C. Chordata
B. Mollusca D. Annelida

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

124

How many kingdoms are there in the modern system of
taxonomy?
A. 2 B. 3 C. 4 D. 5 E. 6

Insects have how many body regions?
A. 2 B. 3 C. 4 D. 5 E. 6

Insects have how many legs?
A. 2 B. 4 C. 6 D. 8

An insect which resembles the adult but is smaller and
has no wings is what?
A. Larva B. Pupa C. Nymph

An insect which looks nothing like the adult and is
worm-like instead is what?
A. Larva B. Pupa C. Nymph

Choose the letters of the stages of complete

metamorphosis and place them IN ORDER in the blank.

A. Adult D. Nymph
B. Egg E. Pupa
C. Larva

Choose the letters of the stages of incomplete
metamorphosis and place them IN ORDER in the blank.

A. Adult 0. Nymph
B. Egg E. Pupa
C. Larva

Which insect lives in a case made of twigs, leaves,
etc. during its aquatic life?

A. Caddisfly C. Mayfly

B. Cranefly D. Stonefly

Which insect is worm-like, has legs, 2 tails, and
obvious gills?

A. Caddisfly C. Mayfly
B. Cranefly D. Stonefly
A snail is a

A. Collector C. Scraper
B. Predator D. Shredder

A clam is a
A. Collector C. Scraper
B. Predator D. Shredder

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

125

The little shrimp-like crustaceans we saw in the river
were

A. Collectors C. Scrapers

B. Predators D Shredders

A cranefly larva is a

A. Collector C. Scraper

B. Predator 0. Shredder

What percentage of all animals are arthropods?

A. 25% B. 50% C. 78% D. 95%
Green algae belong to what kingdom?

A. Fungi D. Monera

B. Plantae E. Protista

C. Animalia

Which of the following algae are filamentous?
A. Desmid C. Splrogyra
B. Diatom D. Volvox

Which of the following algae have “glass“ cases?
A. Desmid C. Splrogyra
B. Diatom D. Volvox

Which of the following algae is colonial and spherical?
A. Desmid C. Splrogyra
B. Diatom D. Volvox

What type of organism is spirogyra?
A. Algae C. Bacteria
B. Bacteria D. Protozoa

What color is spirogyra?
A. Blue-green C. Golden
B. Brown D. Green

What is the structure of spirogyra?
A. Colonial B. Filamentous C. Unicellular

Which is the smallest?
A. Ameba B. Euglena C. Paramecium

 

 

 

126

33. Animal without a spine or baCkbone A. Abdomen

34. Outer covering of arthropod B. Antenna

35. Sense of touch, taste, smell in crayfish C. Antennule

36. Sense of equilibrium in crayfish D. Cheliped

37. Shedding of exoskeleton E. Exoskeleton

38. Middle body section of arthropods F. Foot

39. Last body section of arthropods G. Gills

40. Respiratory organ in aquatic mollusks H. Invertebrate

41. Respiratory organ in aquatic insects I. Mantle

42. Membrane covering body of mollusks J. Molting

43. Claw of crayfish K. Radula

44. Hatchet-shaped digger in clams L. Siphon

45. Secretes shell of mollusk M. Thorax

46. Scraper inside mouth of snail

47. Tubes which move water in and out of clam

48. Floating algae and pr0tozoans A. Autotroph

49. Green pigment found in algae B. Chlorophyll

50. Process by which algae make food C. Eukaryote

51. Group of cells living together D. Heterotroph
and dividing up the work E. Multicellular

52. Group of individual organisms living F. Photosynthesis
together, but still independent G. Plankton

53. One-celled organism H. Prokaryote

54. Contain a nucleus I. Unicellular

55. Make own food

Fill-in and Short Answer:

56. Organisms in the same species can and
produce offspring.

57. Scientific names are in what language?

58. When we say that two organisms are related, it means
that they share a common

59. Which 2 kingdoms contain only organisms which are
multicellular?

60. Why are phytoplankton so important?

61. What shape of diatoms are most common in lakes and
ponds?

62. What is the difference between a snail and a slug?

63. How can you tell if a clam is dead?

64. What is the function of the anterior sucker of a leech?

 

O‘\
Oi

Oi
0t

68.

69.

70.

73.

74.

127
What type of animal is the natural host (prey) for a
leech?

What are two functions of the ex08keleton of
arthropods?

Why are arthropoos considered to be the most successful
phylum of animals?

Where should you look for crayfish eggs?
At what time of year should you look for crayfish eggs?

Why do nymphs or larva usually eat very different foods
from the adults of the same species?

List the classification groups in order starting with
the most general.

Which two classification groups are used in scientific
names?

Sketch Splrogyra.

What is the food for adult mosquitoes of both sexes at

all times?

What is the food for mayfly nymphs?

 

 

 

APPENDIX D

ATTITUDE SURVEY

 

Science
1. Strange i 2
2. Good 1 2
3. Dull 1 2
4. Interesting 1 2
5. Easy 1 2
6. Unimportant 1 2
7. Career 1 2
Laboratory Activities
8. Strange 1 2
9. Good 1 2
10. Bull 1 2
11. Interesting 1 2
12. Easy 1 2
13. Unimportant 1 2
14. Dangerous 1 2
Working in Teams to Solve Problems
15. Good 1 2
16. Strange 1 2
i7. Unimportant 1 2
18. Dull i 2
19. Useful 1 2
20. Busy i 2
21. Difficult 1 2
Scientific Method
22. Strange 1 2
23. Good 1 2
24. Dull 1 2
25. Interesting 1 2
26. Easy 1 2
27. Unimportant 1 2
28. Useful 1 2
Waste Recycling
29. Strange 1 2
30. Good 1 2
31. Important 1 2
32. Easy 1 2
33. Necessary 1 2

OPINION SURVEY ABOUT SCIENCE

129

3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
in Class
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4
3 4

01010101010101 01010101010101 01010101010101 01010101010101

0101010101

Familiar
Bad

Fun
Boring
Difficult
Important
Hobby

Familiar
Bad

Fun
Boring
Difficult
Important
Safe

Bad
Familiar
Important
Fun
Wasteful
Quiet
Easy

Familiar
Bad

Fun

Boring
Difficult
Important
Unnecessary

Familiar
Bad
Unimportant
Difficult
Unnecessary

130

Lawn Fertilizing

34. Strange 1 2
35. Good 1 2
36. Permanent 1 2
37. Easy 1 2
38. Necessary 1 2
39. Dangerous 1 2
Hunting
40. Strange 1 2
41. Good 1 2
42. Dull 1 2
43. Interesting 1 2
44. Easy 1 2
45. Unimportant 1 2
46. Career 1 2
Wildlife Management
47. Strange 1 2
48. Good 1 2
49. Dull 1 2
50. Interesting 1 2
51. Easy 1 2
52. Unimportant 1 2
53. Career 1 2

(0(0(0(0(0(0(0 (0(0(0(0(0(0

(0(0(0(0(0(0(0

.b-b-bkblhb AAAAAA

AbAAAAA

01010101010101 010101010101

01010101010101

Clearcutting forests (this means clearing part

by cutting all the trees down.)

54. Good 1 2
55. Strange 1 2
56. Unnecessary 1 2
57. Ugly 1 2
58. Useful 1 2
59. Permanent 1 2
60. Safe 1 2

Our Local Rivers

61. Polluted 1 2
62. Beautiful 1 2
63. Important 1 2
64. Drinkabie 1 2
65. Uninhabited 1 2

(0(0(0(0(0(0(0

(0(0(0(0(0

AAA-5.5.5.5

butt-AAA

0101010'1010101

0101010101

Familiar
Bad
Temporary
Difficult
Unnecessary
Safe

Familiar
Bad

Fun
Boring
Difficult
Important
Hobby

Familiar
Bad

Fun
Boring
Difficult
Important
Hobby

of a forest

Bad
Familiar
Necessary
Beautiful
Wasteful
Temporary
Dangerous

Clean

Ugly
Unimportant
Undrinkable
Inhabited

131

Directions: Read each of the following statements
carefully. Fill in the circle on your answer sheet which
describes your feelings about the statement.

66.

67.

68.

69.

70.

71.

72.

73.

75.

76.

77.

79.

Most people can leave science to the experts and do not
need to understand how science works.

In order to solve a problem scientifically, scientists
should not use information (data) unless they have
collected it through their OWN research.

Careful observation is less important in modern science
since the development of new instruments like the
electron microscope.

Science deals with all problems and it can provide
answers to all questions.

The knowledge of science is final.

A good scientist must have the aibity to ask the right
questions.

A scientist should only do research on those projects
that will provide something useful.

Since a measurement involves the use of numbers, it
rarely can be wrong.

Scientists assume that if events A and B occur at the
same time, then one must be the cause of the other.

Good science does not require that scientists share
their findings with other scientists.

A good scientist always defends fellow scientists and
their scientific ideas when others say they are wrong.

Scientists do not make errors in their conclusions if
they follow scientific processes.

To make good decisions about how to use our natural
resources (land, forests, wildlife, etc.), all we need
to consider is the scientific information.

The observations a person makes are influenced by his
past experience.

80.

81.

82.

83.

84.

85.

132

If a scientist carefully reports his or her experiment,
other scientists will accept the experimental
conclusions without question.

Hunters today are the cause for most of the decline in
wildlife populations.

If a scientist measures two variables (such as water
temperature and growth of fish) and finds they both
increase or decrease together, it proves changes in
water temperature causes changes in fish growth.

I would like a career working as some type of
scientist.

I would like a career working with wildlife, forests,
rivers or other natural resources.

Big industries like UpJohn and Dow Chemical are the
Michigan polluters and should pay for the clean-up.

 

 

APPENDIX E

STUDENT SIMULATION HANDOUTS

134

BIOLOGY PREDATOR-PREY GAME
OWLS AND MICE

INTRODUCTION:

Animals spend much of their time looking for and
consuming food. Some eat plants, some eat meat, and some
eat both. Many meat-eating animals obtain their meat by
hunting other animals. The hunters are known as predators
and the hunted animals are known as prey.

In this activity you will do a simulation of a
predator-prey relationship, with owls as predators and mice
as prey. In nature, owls and mice are often found living in
forests. The forest in your simulation will be HOOT WOODS.

Owls are excellent hunters. The various kinds of owls
eat many different kinds of animals, including rabbits,
squirrels, rats. mice. shrews, birds, fish, and insects. To
simplify the simulation, you will limit the owls’ food
supply to mice.

PROCEDURE: '

Using masking tape, mark off a square approximately 50
cm on a side on the surface of your lab table. This square
represents Hoot Woods, where the mice and owls live.

You will simulate 25 generations of owls and mice. The
mice can be eaten and the owls can starve. Surviving mice
and owls can reproduce. To make calculations easier, each
surviving mouse will be considered capable of producing one
offspring. In each generation, the surviving mouse
population will double to form the next generation. For
example, if six mice are living in the woods and two are
caught by an owl, then four mice will survive. These four
mice will each produce one offspring, and the next
generation will begin with eight mice. Remember, the number
of offspring is always the same as the number of surviving
mice. At any one time, the maximum mouse capacity of Hoot
Woods is 400 mice.

In order to survive, each owl must catch at least three
mice in every generation. If an owl does not catch three
mice, it will starve. For each three mice that an owl
catches, it will reproduce one offspring. For example, if
an owl catches eight mice it will reproduce two new owls,
making a total of three owls to begin the next generation.

135

At the beginning of EACH generation there must be at
least three mice and one owl in the woods. If the
populations drop below these numbers (by being eaten or
starving), new mice and owls will migrate in. For example,
if Just one mouse survives the first generation, Just one
offspring will be produced, for a total of two mice. One
mouse must migrate in to bring the mice total to three. If
all owls die, one owl must migrate in.

PLAY:

Place the mouse squares at random in Hoot Woods. Then,
from a height of about 30 cm, drop the owl square into the
woods. Try to hit as many mice as you can in one dr0p.

When an owl square fully or partly covers a mouse square(s),
that is a "catch“. If there is more than one owl in a
generation, drop the owl square once for each owl.

Remove and count the number of mice CAUGHT BY EACH OWL
AT EACH DROP. Keep all mice from each owl catch in separate
stacks. Record the data on your chart. You will want to
have different people do the dropping and the recording.

EXAMPLE:

Suppose generation 3 begins with 20 mice and 2 owls.
You make a drop for the first owl and catch 7 mice. 0n the
second drop, the second owl catches only 2 mice. The owls
have caught a total of 9 mice. There are 11 mice left in
Hoot Wooos, and they reproduce 11 mice. The next generation
will start with 22 mice. Because the first owl caught 7
mice. it reproduces 2 offspring for the next generation.
The second owl caught only 2 mice: it starves and does not
survive or reproduce. The data chart line for that
generation would look like this:

Gen. No. No. No. No. No. No.
Mice Owls Mice Owls Surviving Surviving
Start Start Caught Starved Mice + Owls +
Offspring Offspring

3 20 2 9 1 11+11=22 l+2=3

4 22 3

 

 

136

ANALYSIS:

1.

2.

Which population first increases in size?

Describe the pattern of the fluctuations in the sizes of
the two populations.

By looking ONLY at the graph, can you tell which species
is the prey and which species is the predator? How can
you tell?

Which species gets to the largest number of individuals?
Why?

What do you think would happen to the mouse population
in Hoot Woods if the owls were all hunted to extinction?
Why?

Prepare a line graph of the number of mice in each
generation and in a different color the number of owls
in each generation

 

 

APPENDIX E

FILM SOURCES

138
FILM SOURCES

Available from Journal Films

W.

Available from Public Broadcasting System
mm
mm;
Available from Films, Inc.

W ! C . .

Available from Time-Life Films

Cgmmunities of Liying Inings--Ea:ts A - G
Available from ITEC (M Star)

Wald:

Available from Learning Corporation of America

['1 . I ! E

Available from Coronet Instructional Films

H I] “'E l E E !. I !
Available from Encyclopedia Brittanica
Education Corporation

. LIBRRRIES

1IIIIIIIIIIIII

312930088 0966

MICHIGAN STRTE

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