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Honors Biology
Lab Manual
Mt. Lebanon Biology Department
Revised: April 14, 2011
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Table of Contents
2……………………………………………………………………….... Laboratory Safety
4…………………………………………………………………….Lab Report Guidelines
First Semester
5……………………………………………………..What are the constraints on cell size?
8……....What are the similarities and differences between cells from different kingdoms?
13…………………………………………………………………………….Is yeast alive?
15…………………………...Identifying the organic compounds in different food sources
19…………What are the effects of different wavelengths of light on photosynthetic rate?
21…………………………………………………………...Respiration of sugars by yeast
25…………………………………………………….…………………Making Root Beer
27……………………………………………………….…..Case Studies – Trophic Levels
29……………………………………………..How do cell membranes regulate transport?
32…………………..………What environmental factors affect xylem transport in plants?
34…………………………What are the effects of exercise on CO2 output and heart rate?
36……………………………………………………What can you learn by testing urine?
41………….………Which antibiotic or disinfectant is best at controlling E. coli growth?
43……...…………………How do germinating seeds respond to environmental changes?
44……...………………………………………..……………………….Sensory Receptors
49…………………………................................…………….Testing The Nervous System
50……………………………………………….....…..Investigating Invertebrate Behavior
Second Semester
54……………………………………………………………..…..Banana DNA Extraction
56………...During the cell cycle, which stage do onion root cells spend the most time in?
59…...……………………………….......…………………………..Principles of Genetics
66…………………………………………………………...Applying Mendelian Genetics
71……….…..How can blood typing be used to determine parent-offspring relationships?
78……...............................................................................................................Karyotyping
80………………………………………………………………….……Radioactive Decay
83...……….....……………………………………………….Examining the Fossil Record
89………………………...….Natural Selection: The driving force of evolutionary change
101……….……………………………………...……Animal Classification and Diversity
102………………………………………….……………………….……Squid Dissection
105………………………………………………………………...……….Frog Dissection
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Laboratory Safety
Purpose: One of the first things a scientist learns is that working in the laboratory can be an exciting experience. But
the laboratory can also be quite dangerous if proper safety rules are not followed at all times. To prepare you for a safe
year in the laboratory, read over the following safety rules then read them a second time. Make sure you understand
each rule. If you do not, ask your teacher to explain any rules you are unsure of.
Pre-Lab Rules
1. Come prepared to work. Be seated and turn in any items due at the beginning of the period. Be sure that you
understand the procedure (after the introduction) and the possible hazards associated with it.
2. Get and apron or goggles if instructed and check the board for the lab pages to access.
3. Keep your laboratory area clean and free of unnecessary books, papers, and equipment. Place any food, drink,
books, book bags, etc, under the desk.
4. Keep the aisles clear. Push your chair under the desk when not in use.
5. Be serious and alert when working in the laboratory. Never "horse around" in the laboratory.
6. Read all directions for an investigation several times. Follow the directions exactly as they are written. If you are
in doubt about any part of the investigation, ask your teacher for assistance.
7. Never perform activities that are not authorized by your teacher. Obtain permission before "experimenting on
your own."
8. Never handle any equipment unless you have specific permission.
9. Never eat or taste anything in the laboratory unless directed to do so. This includes food, drinks, candy, and gum,
as well as chemicals.
Dress Code
1. Remove or tie back any article of baggy or loose clothing or jewelry that can hang down and touch chemicals and
flames.
2. Long pants are also recommended, but not required in the lab.
3. It is recommended that jewelry not be worn in the lab.
4. Many materials in the laboratory can cause eye injury. To protect yourself from possible injury, wear safety
goggles whenever you are working with chemicals, burners, or any substance that might get into your eyes.
5. Wear a laboratory apron or coat whenever you are working with chemicals or heated substances.
6. Tie back long hair to keep your hair away from any chemicals, burners and candles, or other laboratory
equipment.
7. Do not wear sandals or open toed shoes in the laboratory. Never walk around the laboratory barefoot or in
stocking feet.
First Aid & Medical Information
1. Become aware of the location of the first aid kit, safety shower, and eye wash station. But remember that your
teacher should administer any required first aid due to injury. Or your teacher may send you to the school nurse
or call 911.
2. Report all accidents, no matter how minor, to your teacher immediately.
3. Know how to call the principal, nurse, and 911 in case of an emergency.
4. After the introduction to the lab exercise, notify your instructor of any medical concerns, allergies, or asthma
problems that are applicable that investigation.
5. It is recommended that contact lenses not be worn in the laboratory
6. Learn what to do in case of specific accidents such as getting acid in your eyes or on your skin. (Rinse acids off
your body with lots of water.)
Fire Safety
1. Maintain a clean work area and keep all materials away from flames.
2. Know where and how to report a fire. Find out the location of the fire extinguisher, fire alarm, fire blanket, fire
exit route, and phone. If an emergency occurs, know how to call 911, the principal, or nurse. Report any fires to
your teacher at once.
3. Never use a heat source such as a candle, burner, or hot plate without wearing safety goggles.
4. Look for the Kimex or Pyrex labels before heating glassware. This label indicates that the glassware is safe at
high temperatures.
5. Never heat a chemical you are not instructed to heat. A chemical that is harmless when cool can be dangerous
when heated.
6. Never heat liquid in a closed container. The expanding gasses produced may blow the container apart, injuring
you and others.
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7. Point a test tube or glassware that is being heated away from you and others. Chemicals can splash or boil out of
heated glassware.
8. Never reach across a flame.
9. Make sure you know how to light a Bunsen burner and turn on the gas jets. Your teacher will demonstrate the
proper procedure for lighting a Bunsen burner when that procedure is encountered in lab. If the flame leaps out of
a burner toward you, turn the gas off immediately. Do not touch the burner. It may be hot. Never leave a Bunsen
burner, hot plate, or open flame unattended. Someone needs to be watching it at all times.
10. Never pick up a container that has been heated without first holding the back of your hand near it. If you can feel
the heat on the back of your hand, the container may be too hot to handle. Use a clamp, tongs, or heat-resistant
gloves when handling hot containers.
Using Chemicals Safely
1. Keep your hands away from your face, eyes, mouth, and body while using chemicals or preserved specimens.
2. Never mix chemicals for the "fun of it." You might produce a dangerous, possibly explosive substance.
3. Never touch, taste, or smell a chemical that you do not know for a fact is harmless. Many chemicals are
poisonous. If you are instructed to note the fumes in an investigation, gently wave your hand over the opening of
a container and direct the fumes toward your nose. Do not inhale the fumes directly from the container.
4. Use only those chemicals needed in the investigation. Keep all lids closed when a chemical is not being used.
5. Never use the same transfer devices (i.e., pipettes, test tubes) for different chemicals unless they are washed
thoroughly before the next transfer.
6. Take extreme care not to spill any material in the laboratory. If spills occur, ask your teacher immediately about
the proper cleanup procedure. Never simply pour chemicals or other substances into the sink or trash container.
7. Dispose of all chemicals as instructed by your teacher. To avoid contamination, never return chemicals to their
original containers.
8. Solid chemicals and metals are to be disposed of in the proper waste containers, not in the sink. Check the label
of all waste containers twice before adding your chemical waste to it.
9. Be extra careful when working with acids or bases. Pour such chemicals over the sink, not over your work bench
or notebooks.
10. When diluting an acid, pour the acid into water. Never pour the water into the acid.
11. Rinse any acids off your skin or clothing with water. Immediately notify your teacher of any acid spill.
Glassware
1. Never eat or drink from laboratory glassware. Clean glassware both before and after each investigation.
2. Never force glass tubing into a glass stopper. This may cause the glassware to break injuring you and possibly
others. Your teacher will demonstrate the proper way to insert tubing into a stopper when encountered in lab.
3. Keep in mind that hot glassware will not appear hot. Never pick up glassware without first checking to see if it is
hot. Use the proper equipment for handling hot glassware, i.e., test tube holders, heat resistant gloves, etc.
4. Report all broken glassware to your teacher immediately. Dispose of the glassware in the proper container.
Sharp Instruments
1. Handle scalpels, scissors, razor blades, probes, and all sharp equipment with extreme care. Never cut material
toward you; cut away from you.
2. Notify your teacher immediately if you cut yourself or receive a cut.
3. Remember that scalpels, razor blades, probes, etc, are laboratory tools, but are considered weapons when seen
outside of the laboratory classroom.
Living Organisms
1. No investigations that will cause pain, discomfort, or harm to mammals, birds, reptiles, fishes, and amphibians
should be done in the classroom or at home.
2. Treat all living things with care and respect. Do not handle any organism in the laboratory unless given
permission to do so.
3. Your teacher will instruct you on the proper handling of each species brought into the classroom.
4. Treat all microorganisms as if they were harmful. Use antiseptic procedures, as directed by your teacher, when
working with microbes and bacteria. Dispose of all bacterial specimens as directed by your teacher.
5. Be sure to wash your hands after handling any organisms in lab.
End of Lab Rules
1. With 5 minutes remaining in the period, clean up your work area and return all equipment to its proper place.
2. Wash hands, lab benches, and sink areas after every investigation.
3. Use specified antiseptic techniques if bacterial microbes were used in the lab.
4. Turn off all burners and faucets before leaving the laboratory. Check that the gas line leading to the burner is off
as well.
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Lab Report Guidelines
Title
Describes lab content concisely, adequately, appropriately
Objectives
Includes the question to be answered by the lab
Successfully establishes the scientific concept of the lab
Effectively presents the objectives and purpose of the lab
Hypotheses
Includes both null and alternative hypothesis
Hypothesis is based on research and/or sound reasoning
Hypothesis is testable.
States hypothesis and provides logical reasoning for it
Methods
Includes materials and summary of procedure
Gives enough details to allow for replication of procedure
Results
Includes data tables, visual representations of data, and statistical analysis
Presents visuals clearly and accurately
Presents verbal findings clearly and with sufficient support
Results and data are clearly recorded, organized so it is easy for the reader to see trends.
All appropriate labels are included
No interpretation
Discussion
Interpretations: Discuss what the trends in your data indicate. Discuss trends related to the question
at hand as well as any interesting unrelated trends you may have seen that are not directly related to the
question at hand.
Conclusion: State whether your hypothesis was supported or refuted and how confident you are in this
claim. If your results were inconclusive, discuss why. Develop reasoning as to why results show what
they do. Discuss the theory behind your results.
Mistakes: These could be flaws in your design and/or mistakes in your execution, both of which can
be fixed by redesigning or repeating the experiment. If you were unable to fix your mistakes during
the experiment, mention them here.
Error: Sources of error are factors that lower the quality of your data that are more or less out of your
control. No data is perfect; all experiments have sources of error.
Suggestions: If your experiment was inconclusive, suggest ways to redesign or repeat the experiment
in order to make it conclusive. If your results were conclusive (hypothesis was either supported or
refuted) but not extremely confident, suggest ways to improve this confidence. If your conclusion was
sufficiently confident, suggest a new experiment by asking a follow-up question. Also, suggest any
new hypotheses that might arise from any interesting trends you noticed that were unrelated to the
initial hypothesis.
Applications: Discuss how your conclusions to this lab relate to or can be applied to real life
situations. Discuss why the knowledge gained from this lab is useful.
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What are the constraints on cell size?
Objective
Determine how different cell sizes affect nutrient intake and output.
Materials list (per group)
Each class will have four students. Within each group, two students will run
experimental setup 1 and two students will run experimental setup 2.
Experimental Group I
Plastic Spoon 250 ml beaker
3 Agar-Phenolphthalein blocks (1 cm, 2cm, and 3cm sizes)
100 ml of 0.4% sodium hydroxide solution
Paper towel Scalpel
Metric ruler
Experimental Group II
Plastic Spoon
3 Agar-Sodium chloride blocks (1 cm, 2cm, and 3cm sizes)
1-600 ml beaker
Distilled water bottle
Paper towel Scalpel
Metric ruler Ring Stand
Utility clamp Vernier probe for conductivity
Laptop plus Vernier interface equipment
Power cord, USB cord, Lab Pro
Materials list (per class)
12 plastic spoons
6 ice cubed shaped agar-phenolphthalein blocks
6 ice cubed shaped agar-sodium chloride blocks
600mL of 0.4% sodium hydroxide solution
6 distilled water bottles
6-250mL beakers 6-600mL beakers
12 metric rulers 12 scalpels
6 ring stands 6 utility clamps
6 Vernier setups including laptops and conductivity probes
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Procedure – Experimental Group I: Testing Sodium Hydroxide Transport
1. Using the plastic spoon, place the 3 agar-phenolphthalein blocks in the beaker. Pour
100 mL of the 0.4% sodium hydroxide solution over the blocks. Allow the blocks to
remain in the solution undisturbed for 10 minutes.
2. After 10 minutes, remove the blocks with the plastic spoon. Place them on the paper
towel and blot them dry.
3. Cut each block in half with the scalpel. Using the metric ruler, measure the distance
in millimeters that the pink color has diffused into each block. Record this
measurement in the appropriate data table.
Procedure – Experimental Group II: Testing Sodium Chloride Transport
1. Set up the utility clamp, Conductivity Probe, and ring stand as shown.
2. Connect the Conductivity Probe to the computer interface. Prepare
the computer for data collection by opening the file “02 Limits on
Cell Size” from the Biology with Vernier folder of Logger Pro.
3. Set the selector switch on the side of the Conductivity Probe to the
0 – 20000 µS/cm range.
4. Pour 300mL of tap water into the 600mL beaker. Position the
Conductivity Probe in the water so the tip is about 2 cm from the
bottom of the beaker.
5. Place the solid agar cube sample in the beaker and begin data
collection by clicking . Stir the water using the stirring rod. Data collection
will automatically end after two minutes.
6. Determine the rate of ion exchange by performing a linear regression of the data:
a. Click the Linear Fit button, , to perform a linear regression. A floating box will
appear with the formula for a best fit line.
b. Record the slope of the line, m, as the rate in the appropriate data table..
7. Empty the water from the beaker and rinse it thoroughly. Rinse the probe with clean,
distilled water. Blot the outside of the probe tip dry with a tissue or paper towel. It is
not necessary to dry the inside of the hole near the probe end.
8. Move your data to a stored run. To do this, choose Store Latest Run from the
Experiment menu.
9. Repeat Steps 4 – 8 for the 2cm agar cube.
10. Repeat Steps 4 – 8 for the 3cm agar cube.
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Data Tables and Calculations
Agar Blocks - Calculations
Cube Size Surface Area Volume Surface Area-to-Volume
(cm2) (cm3) Ratio
1 cm
2 cm
3 cm
Surface area = number of surfaces x length x width
Volume = length x width x height
Surface area-to-volume ratio should be listed with a colon (ie. 3:1 or 5:1, etc).
Data - Experimental Group I: Testing Sodium Hydroxide Transport
Cube Size Distance traveled by Ratio of distance traveled- Most efficient in intake of
sodium hydroxide to-volume chemicals
1 cm
2 cm
3 cm
The most efficient cube size will be the one which has the highest ratio of distance traveled to
volume
Data - Experimental Group II: Testing Sodium Chloride Transport
Cube Size Rate (m) Ratio of conductivity-to- Most efficient in export of
(µS/cm/s) volume chemicals
1 cm
2 cm
3 cm
The most efficient cube should be the one which results in the highest conductivity-to-volume
ratio
Discussion
1. How did the experiments using sodium hydroxide and sodium chloride model intake
and output in cells?
2. Define efficiency in terms of cell intake and output. How does this lab measure
efficiency?
3. What aspect of cells that we measured determines their ability take in and release
materials?
4. What is the relationship between efficiency and cell size? What evidence do you
have?
5. What are the constraints on cell size? What is the smallest a cell can be? Why? What
is the largest a cell can be? Why?
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What are the similarities and differences between cells from
different kingdoms?
Introduction
Ever since the first microscope was used, biologists have been interested in
studying the cellular organization of all living things. After hundreds of years of
observations by many biologists, the cell theory was developed. The cell theory states
that the cell is the structural and functional unit of living things. Cells contain structures
called organelles that carry out life processes. In cells, similarities and differences exist
because of varied life functions. There are two major divisions into which all cells fall –
prokaryotic and eukaryotic.
Prokaryotic cells are cells the lack a nucleus and membrane-bound organelles.
Bacteria and related microorganisms are prokaryotes. Eukaryotic cells are cells that
contain a nucleus and membrane-bound organelles. Organisms such as animals, plants,
fungi, and protists are all eukaryotic.
Objectives
Observe cells on various slides to examine the differences between prokaryotic
and eukaryotic cells and plant and animal cells
Compare and contrast the structures of different cells
Materials (per group)
Microscope Medicine dropper Rulers
Glass slide Coverslip Methylene blue stain
Lens paper Toothpicks Forceps
Water Elodea leaf
Prepared slides of prokaryotic and eukaryotic cells
Pre-Lab Part I: Parts of the Compound Light Microscope
Use the diagram of the microscope to familiarize yourself with the various parts and their
functions.
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Pre-Lab Part II: Magnification of the Lenses
It is often difficult to know the actual size of an object being observed. Magnification
causes us to lose the idea of actual size. You cannot hold up a ruler to a paramecium or a
plant cell while it is under the microscope. There size must be measured indirectly – that
is, it must be compared to the size of something you already know. The diameter of the
microscope field seen through the eyepiece is a convenient standard to use. To measure
objects under a microscope, a unit called micrometers (μm) is used.
Complete the following data table. To determine the total magnification, multiply the
magnification of each objective by the magnification of the eyepiece.
Objective Magnification of Magnification of Total
Objective Eyepiece Magnification
Low-power
Medium-power
High-Power (Oil)
Part I: Measuring with the Compound Light Microscope
Procedure
Microscopic measurements are frequently of great importance to the biologist. The
smallest unit of macroscopic metric measurement is one millimeter (mm), or about 1/25
in. However, this is an extremely large unit for microscopic measurement. For measuring
microscopic materials, the biologist uses a unit known as a micron (.u), which is 0.001
mm. There are 1000 um in 1 mm.
Research microscopes are often equipped with an optical micrometer,
a glass disk with a micron scale, which is placed in the ocular, as
shown. By moving the slide, an object may be placed along the scale
and measured accurately. Without an ocular micrometer, however,
you can determine the approximate size of many specimens by
comparing them with the known diameter of the low-power and high-
power fields.
Using a metric ruler, determine the diameter for the field of view at low, medium, and
high power. Record your observations.
Low Power Medium Power High Power
____ ____ ____
um um um
P a g e | 10
Part II: Observing and Comparing Cells
Procedure
1. Using appropriate technique, obtain a microscope and prepare it for use.
2. Obtain various prepared slides from your teacher for observation: two types of
bacteria, one protist, and one fungus. Locate each of the cell types under the
microscope.
a. In the data table, write the name of each type of cell (ex. E. coli) that you
examined. Describe the general shape and estimate the size of the cell in
the spaces provided. Be sure to determine what power magnification you
are best able to observe the cells under in order to accurately estimate their
sizes.
b. At high power, look for structures unobservable at low power. Put a
check mark next to the cell structures that you are able to observe. These
are difficult. Do your best.
c. Based on your observations, decide if the cell is prokaryotic or eukaryotic
and record this in the data table.
d. In the appropriate place in the observation section, draw and label what
you see under the microscope in color. Be sure to record the
magnification of the microscope.
3. Examining Plant Cells
a. Place a drop of water in the center of a clean glass slide.
b. With forceps, remove a leaf from the Elodea or Java Moss plant and place
it on the drop of water on the slide. Make sure that the leaf is flat.
c. Carefully place a coverslip over the drop of water and leaf.
d. Once the slide has been prepared, repeat step number 2.
4. Examining Animal Cells
a. Place a drop of water in the center of a clean glass slide.
b. Using the flat end of the toothpick, gently scrape the inside of your cheek.
Do not draw blood. Cells should be stuck to your toothpick although it
may appear to be just saliva.
c. Stir the water on the slide with the end of the toothpick to mix the cheek
cells with the water. Dispose of the toothpick as instructed by your
teacher.
d. Put one drop of methylene blue stain on top of the drop of water
containing the cheek cells. Be careful not to stain your hands and
clothing.
e. Wait one minute, then carefully place a coverslip over the stained cheek
cells.
f. You may remove excess stain from under the coverslip by placing a piece
of paper towel under the edge of the coverslip. The stain will be absorbed
by the paper towel. Dispose of the paper towel after use.
g. Once the slide has been prepared, repeat step number 2.
5. Clean and dry all of the slides and coverslips.
6. Return microscopes to your storage areas.
P a g e | 11
Data
Cell Structures
Nuclear Envelope
Cell membrane
Size Prokaryotic or
Cell Type Shape
Cytoplasm
(um) Eukaryotic
Vacuoles
Cell wall
Nucleus
Plastids
Observations
Slide 1 – Bacteria Mag. Slide 2 – Other Mag.
Cell Type Cell Type
Slide 3 – Protista Mag. Slide 4 – Fungi Mag.
Cell Type Cell Type
P a g e | 12
Slide 5 – Plant Mag. Slide 6 – Animal Mag.
Cell Type Cell Type Cheek Epithelial Cells
Discussion
1. Based on your observations, do all cells have the same shape and size? Provide
examples to support your answer. Explain why or why not.
2. What structures are common to all cells? What structures are specific to certain
cells? Elaborate for each.
3. Why are stains such as methylene blue used when observing cells under the
microscope?
4. What is the advantage of using a wet-mount preparation instead of a dry mound
preparation in the study of living cells?
5. In general, the surface of a tree has a harder “feel” than does the surface of a dog.
What cell characteristic of each organism can be used to explain this difference?
6. Classify the following unknown cells. Be as specific as possible, but if more than
one group of organisms applies, list all possibilities.
a. Cell wall, nucleus, mitochondria – 30 um.
b. Rod shaped, cell wall – 2 um.
c. Cell membrane, no cell wall, nucleus, ribosomes – 45um.
P a g e | 13
Is yeast alive?
Objective
To find out whether yeast is alive, we first need to think about what makes something
alive. There are several characteristics of living things. All living things must: (1) be
comprised of cells, (2) must reproduce, (3) use energy, (4) respond to their environment,
and (5) grow and develop. We will use these characteristics to determine if yeast is alive.
Materials
4 – 16 x 150mm test tubes Test tube racks
Plastic droppers Glass slides
Cover slips Lens paper
Flour Salt
Baking Soda Sugar
Distilled water Dry yeast packets
Metric rulers Microspoons
Digital Microscopes Scotch Tape
Petri Dishes w/ YED Agar Markers
Digital Camera 7” Balloons – 4/group
Procedures
I. Do yeast contain cells?
1. Create a wet mount slide of yeast and observe it under the microscope. Draw your
observations or create a digital micrograph. These should be captured in high power.
If using digital microscopes, include your name(s) and magnification on the digital
image before it is captured. Include your images in your report.
II. Do yeast grow, develop, and reproduce?
1. Obtain an agar plate containing yeast media. Label the bottom of the dish with your
name, teacher, and class period.
2. Add 5 drops of the warm yeast solution to the plate.
3. The plates should be photographed with a digital camera on top of a white sheet of
paper that has your name(s), teacher, and period. Be sure to note that this is your
initial observation.
4. Your plates will be incubated at 37° C until the next class. (Formula: F=9/5C +32)
5. After at least one day, inspect your plate. Take another digital picture of your plate
after the incubation period using the same methods as before. Be sure to note that
this is your final observation. Compare your two digital photographs. Both, the
before and after incubation photos should be included in your report.
P a g e | 14
III. Do yeast utilize energy and respond to their environment?
Organisms that obtain energy from organic food sources give of gases, such as CO2, as a
waste product. We will carry out a test for yeast metabolism in different environments.
In other words, we will be indirectly testing whether yeast can utilize sugar as a food
source. Then we will test if there are differences in metabolism under different situations
as a response.
1. Set up four test tubes in a test tube rack.
2. Label each tube with a number, 1-4, and group name. All test tubes will contain yeast
and water (3/4 of the tube should be filled with warm yeast solution). These amounts
should be consistent in each tube. Test tubes 2-4 will also contain sugar. Test tubes 3
and 4 will also have either salt, flour, or baking soda (you choose). What amounts of
each variable should be added to the tubes?
3. Hold your thumb over the test tubes and shake them vigorously to thoroughly mix the
contents. Cover the opening of each test tube with a balloon to catch any gas that is
formed. Tape the balloon in place so it cannot be pulled off.
4. Allow the tubes to sit overnight at room temperature. Record the diameter of the
balloon the next day in the table below. This table should be included in your report.
TEST TUBES BALLOON DIAMETER
(All tubes contain yeast and water) Over 24 hours
Test tube 1: Control – Yeast solution only
Test tube 2: Sugar
Test tube 3: Sugar and Environmental
Condition A
Test tube 4: Sugar and Environmental
Condition B
In your lab report, be sure to include the following items.
Results
Part I: 1 Digital micrograph picture or drawing
Part II: 2 Digital pictures (initial and final)
Part III: Balloon Diameter Data Table
Discussion
1. Describe your observations for each part of the experiment.
2. Explain whether your data confirms if yeast is alive.
3. Describe sources of error.
4. Suggest further research.
P a g e | 15
Identifying the organic compounds in different food sources
Pre-Lab Discussion
The most common organic compounds found in the living body are lipids,
carbohydrates, proteins, and nucleic acids. Common foods, which often consist of plant
materials or substances derived from animals, are also combinations of these organic
compounds. Simple chemical tests with substances called indicators can be conducted to
determine the presence of organic compounds. A color change of an indicator is usually
a positive test for the presence of an organic compound.
Objective
Use several indicators to test for the presence of lipids, carbohydrates, and
proteins in particular foods
Materials
10 Test tubes Test Tube rack
Masking tape Hot plate
Iodine solution 20 ml honey solution
20 ml egg white solution 20 ml corn oil
20 ml lettuce solution 20 ml gelatin solution
20 ml potato solution 20 ml melted butter
20 ml distilled water 20 ml apple juice solution
Brown paper towels 20 ml unknown substance
Biuret Reagent Sudan IV Stain
Benedict’s Solution 600 ml beaker
Procedure
I. TESTING FOR LIPIDS (Paper towel Test, Sudan Stain test)
A. Paper Towel Test
1. Obtain 10 test tubes and place them in a test tube rack. Wrap masking tape 1-1/2
times around the tube and label each. Be sure that the tape is fastened properly.
Label the paper towel as follows:
Honey Egg White Corn Oil Lettuce Gelatin
Butter Potato Apple Juice Distilled H2O Unknown
2. Fill each test tube with a “finger width” of the substance indicated.
3. Use your thumb to invert the tube and place a thumbprint of the food on the paper
towel in the correct box. The “smear” should be about the size of a quarter. Do
not invert the tubes over the paper towel to avoid spillage. Set the paper aside
until all other data for the lab is collected.
P a g e | 16
4. Come back to this section after all other data has been collected for the lab. Hold
the paper towel up to the light. You will notice that some foods leave a
translucent spot on the brown paper. The translucent spot indicates the presence
of lipids.
5. Place a check mark on the data table for those substances, which have shown the
presence of lipids for the paper towel test.
B. Sudan Test for Lipids
1. Add a toothpick scooping of Sudan IV Stain to each of the 10 tests tubes and
shake vigorously. CAUTION: Sudan IV will stain skin and clothing. Use caution
when handling. Sudan IV stain will change the solution of a reddish color in the
presence of lipids.
2. Record the resultant colors and place a check in the appropriate box to indicate
the substances, which contain lipids.
3. Wash all test tubes thoroughly.
TESTING FOR CARBOHYDRATES (Iodine Test, Benedicts Test)
A. Iodine Test
1. Refill each cleaned test tube with a “finger width” of the substance indicated on
the masking tape label. Add 5 drops of iodine solution to each tube and shake.
Iodine will change to a dark blackish-blue color in the presence of starch.
CAUTION: Iodine will stain skin and clothing. Use caution.
2. In the data table, record the color of all tubes. Place a checkmark beside each
tube that contains carbohydrates.
3. Wash all tubes thoroughly.
B. Benedict’s Test (hot water bath)
1. Set up a 600 ml beaker (200 ml of tap water) water bath on a hot plate as shown
below. Heat the water bath to a gentle boil. CAUTION: Use extreme care when
working with hot water. Do not let the water splash onto your hands.
2. While the water bath is heating, fill each of the clean tubes with a “finger width”
of the substance on the masking tape. Then add 10 drops of Benedict’s solution
to each of the tubes.
3. Place the tubes in the heated water bath for 2 minutes.
4. Using test tube holders, remove the tubes from the bath. When heated, Benedict’s
solution will change color to a muddy, rusty orange-ish color in the presence of
carbohydrates. Record all test tube colors in the data table and place a check by
those foods that contain carbohydrates.
5. After they have cooled, wash the test tubes thoroughly.
TESTING FOR PROTEINS (Biuret’s Test)
A. Biuret’s Test
1. Place a “finger width” of the appropriate substance in each of the labeled test
tubes. Add 10 drops of Biuret reagent to each tube. CAUTION: Biuret contains a
strong base. If you get it on your skin, wash it off immediately with water. Shake
the tubes vigorously.
P a g e | 17
2. Biuret reagent changes to a blue-violet color in the presence of protein. In the
data table, record all test tube colors and place a check mark next to any
substances that contain proteins.
3. Wash the test tubes thoroughly.
(Finish your paper towel lipid test.)
Observations
Data
Substance Lipid Tests Carbohydrate Tests Protein Test
Complex Simple
Paper Lipids Iodine Biuret Proteins
Sudan Color Carbs Benedicts Color Carbs
Towel Present? Color Color Present?
present? Present?
Honey
Egg White
Corn Oil
Lettuce
Gelatin
Butter
Potato
Apple Juice
Distilled
Water
Unknown
Discussion
1. Which test substances contain lipids?
2. Which test substances contain carbohydrates?
3. Which test substances contain protein?
4. Which test substance did not test positive for any of the compounds?
5. What is the purpose of using distilled water as one of your test substances?
6. What do all indicators have in common? What do indicators do?
P a g e | 18
7. Your brown bag lunch has a large, translucent spot on the bottom. What
explanation could you give for this occurrence?
8. What conclusion could you make if a positive test for any of the organic
compounds occurred in the test tube containing only distilled water?
9. A very thin slice is removed from a peanut and treated with Sudan stain. Then a
drop of Biuret reagent is added to the peanut slice. When you examine the peanut
slice under the microscope, patches of red and blue violet are visible. What
conclusions can you draw from your examination?
10. When a police officer determines that a homicide had occurred on some
individual, then they may request that the food found in their victim’s stomach be
tested. We in fact tested this food as our unknown. So where should we tell the
police that the victim had eaten. Did the victim just eat at a greasy burger at the
City Diner, fettucini alfredo at the Italian pasta house, or barbeque chicken from
Hickory Farm? Explain your reasoning.
11. Why would someone on a diet eat lettuce? Explain.
P a g e | 19
What are the effects of different wavelengths of light on
photosynthetic rate?
Objective
Determine how different colors of light effect photosynthetic rate
Materials list (per group)
1-Ringstand
1-O-Ring
1-light
1-shoebox (provided by students)
1 -4” x 4”squares of colored cellophane (red, blue, and green)
5-150 ml beakers
160 ml 0.2% Sodium bicarbonate solution (40 ml per beaker)
50 spinach disks (spinach provided by instructor) with O2 removed
Procedure – Part I: Preparing the spinach disks
1. Each group of 4 students needs to prepare 50 spinach disks total for their 5
treatments. Stack the spinach leaves on the desk and punch holes in them using
the potato core device. Be sure to punch about 10 extra for the experiment.
Discard any incomplete “holes”.
2. Place all spinach disks into a sodium bicarbonate vacuum for 20 minutes. This
removes the Oxygen from the disks. Once removed from the vacuum all of the
disks should sink to the bottom of the Erlenmeyer flask. Repeat for additional
time if necessary.
Procedure – Part II: Setting up the experiment
1. Cut three 3” x 3” squares in the bottom of the shoebox as instructed by your
teacher. Cut 3 different colors of cellophane (red, blue, green) and tape them over
the openings in the box. The fourth setup will receive white light and the fifth
will not receive any light.
2. Next, divide the inside of the shoebox into 6 even sections using construction
paper.
3. Fill each beaker with 40 ml of sodium bicarbonate solution. Place 10 oxygen
removed spinach disks in each beaker. (They should sink to the bottom. If they
do not, then discard, and get additional disks).
4. Invert the shoebox and cover the beakers. Each beaker should be located in a
different quadrant of the shoebox.
P a g e | 20
5. Set up the ring stand, o-ring, and light as instructed by your teacher. At what
distance should the light be placed? (Caution: Do not put the light too close to the
shoebox or it may catch fire.)
6. Wait 50 minutes and then remove the shoebox. Without disturbing the beakers,
count the number of disks that are floating (i.e., not 100% flat on the bottom of
the beaker).
7. Create a class data table and record the percent of floating disks in found in each
color of light for the entire class.
8. Clean up the work area and analyze the class data.
Discussion
1. What is the purpose of using the beaker of disks in the dark?
2. What color of light produced the highest percent of floating disks?
3. Which wavelength of light was most effective in promoting photosynthesis? Why?
4. Which wavelength of light was least effective in promoting photosynthesis? Why?
5. Was your initial hypothesis supported or rejected? Why?
6. Describe at least 2 sources of error and 2 ways to improve this experiment.
P a g e | 21
Respiration of Sugars by Yeast
Introduction
Yeast are able to metabolize some foods, but not others. In order for an organism to make
use of a potential source of food, it must be capable of transporting the food into its cells.
It must also have the proper enzymes capable of breaking the food’s chemical bonds in a
useful way. Sugars are vital to all living organisms. Yeast are capable of using some, but
not all sugars as a food source. Yeast can metabolize sugar in two ways, aerobically, with
the aid of oxygen, or anaerobically, without oxygen.
In this lab, you will try to determine whether yeast are capable of metabolizing a variety
of sugars. When yeast respire aerobically, oxygen gas is consumed and carbon dioxide,
CO2, is produced. You will use a CO2 Gas Sensor to monitor the production of carbon
dioxide as yeast respire using different sugars. The four sugars that will be tested are
glucose (blood sugar), sucrose (table sugar), fructose (fruit sugar), and lactose (milk
sugar).
Objectives
Use a CO2 Gas Sensor to measure concentrations of carbon dioxide
Determine the rate of respiration by yeast while using different sugars
Determine which sugars can be used as a food source by yeast
CO2 Gas Sensor
Figure 1
Materials
computer 600 mL beaker (for water bath)
Vernier computer interface Beral pipettes
Logger Pro hot and cold water
Vernier CO2 Gas Sensor thermometer
250 mL respiration chamber four 10 100 mm test tube
5% starch, glucose, sucrose, lactose, and yeast suspension
fructose sugar solutions
P a g e | 22
Procedure
1. Obtain six test tubes and label them T, G, S, F, L, and W.
2. Obtain the five sugar solutions: starch, glucose, sucrose, fructose, and lactose.
a. Place 2 mL of the starch solution in test tube T.
b. Place 2 mL of the glucose solution in test tube G.
c. Place 2 mL of the sucrose solution in test tube S.
d. Place 2 mL of the fructose solution in test tube F.
e. Place 2 mL of the lactose solution in test tube L.
f. Place 2 mL of distilled water in test tube W.
3. Obtain the yeast suspension from the water bath. The water bath ensures that the
yeast will remain at a constant and controlled temperature (38°C). Gently swirl the
yeast suspension to mix the yeast that settles to the bottom. Put 2 mL of yeast into
each of the six test tubes. Gently swirl each test tube to mix the yeast into the
solution.
4. Set the six test tubes into the water bath.
5. Incubate the test tubes for 10 minutes in the water bath. Keep the temperature of the
water bath constant. If you need to add more hot or cold water, first remove as much
water as you will add, or the beaker may overflow. Use a beral pipet to remove excess
water. While the test tubes are incubating, proceed to Step 7.
6. Connect the CO2 Gas Sensor to the computer interface. Prepare the computer for data
collection by opening the file “12A Yeast Respiration” from the Biology with Vernier
folder of Logger Pro.
7. When incubation is finished, use a beral pipet to place 1 mL of the solution in test
tube T into the 250 mL respiration chamber. Note the temperature of the water bath
and record as the actual temperature in Table 1.
8. Quickly place the shaft of the CO2 Gas Sensor in the opening of the respiration
chamber. Gently twist the stopper on the shaft of the CO2 Gas Sensor into the
chamber opening. Do not twist the shaft of the CO2 Gas Sensor or you may damage
it.
9. Begin measuring carbon dioxide concentration by clicking . Data will be
collected for 4 minutes.
10. When data collection has finished, remove the CO2 Gas Sensor from the respiration
chamber. Fill the respiration chamber with water and then empty it. Make sure that all
yeast have been removed. Thoroughly dry the inside of the chamber with a paper
towel.
P a g e | 23
11. Determine the rate of respiration:
a. Move the mouse pointer to the point where the data values begin to increase. Hold
down the left mouse button. Drag the pointer to the end of the data and release the
mouse button.
b. Click on the Linear Fit button, ,to perform a linear regression. A floating box
will appear with the formula for a best fit line.
c. Record the slope of the line, m, as the rate of respiration in Table 1.
d. Close the linear regression floating box.
e. Share your data with the class by recording the sugar type and respiration rate on
the board.
12. Move your data to a stored run. To do this, choose Store Latest Run from the
Experiment menu.
13. Use a notebook or notepad to fan air across the openings in the probe shaft of the CO2
Gas Sensor for 1 minute.
14. Repeat Steps 8 – 14 for the other five test tubes.
Data
Table 1: Individual Results
Sugar Tested Respiration Rate
(ppm/min)
Starch
Glucose
Sucrose
Fructose
Lactose
Water (control)
Table 2: Class Averages
Sugar Tested Respiration Rate
(ppm/min)
Starch
Glucose
Sucrose
Fructose
Lactose
Water
P a g e | 24
Results
1. When all other groups have posted their results on the board, calculate the average
rate of respiration for each solution tested. Record the average rate values in Table 2.
2. On Page 2 of the experiment file, make a bar graph of rate of respiration vs. sugar
type. The rate values should be plotted on the y-axis, and the sugar type on the x-axis.
Use the rate values from Table 2.
Discussion
1. Considering the results of this experiment, do yeast equally utilize all sugars?
Explain.
2. Why do you need to incubate the yeast before you start collecting data?
3. Why could certain carbohydrates be used successfully for respiration by yeast, and
others not?
4. How does the absence or presence of certain enzymes in yeast can affect their ability
to use certain carbohydrates?
5. How are monosaccharides, disaccharides and polysaccharides used differently by
yeast cells?
6. How is sugar processed differently in yeast in the absence of oxygen.
7. Why would all yeast would be lactose intolerant, while only some humans are
considered lactose intolerant.
8. Yeast lives in many different environments. Make a list of some locations where
yeast might naturally grow. Estimate the possible food sources at each of these
locations
P a g e | 25
Making Root Beer
A Practical Example of Anaerobic Respiration
Introduction
History of Root Beer: Root beer was made by our forefathers by soaking Sasafras (a type
of tree) root in water, and adding sugar and yeast (for carbonation). In the early 1900's
however, scientists discovered that safrole, a chemical found in Sassafras root, was a
carcinogen (which means it is a cancer causing agent.) Now, a mixture of other herbs and
spices makes up "root beer extract" which is what we now use to make homemade root
beer.
Background Information: There are two types of respiration: aerobic (requiring oxygen)
and anaerobic (without oxygen). Yeast cells (a type of fungus) obtain energy from
glucose (sugar) by a specific anaerobic process called fermentation. There are two types
of fermentation, lactic acid fermentation (which occurs in muscle cells when they are
oxygen deprived), and alcoholic fermentation, which is involved in the making of food
products. Alcoholic fermentation begins after glucose diffuses into the yeast cell. The
glucose is broken down into two 3-carbon molecules called pyruvic acid. The pyruvic
acid is then converted to CO2, ethanol, and energy for the yeast cell. Don't get excited,
students, there is very little ethanol in this root beer.
Doesn’t anaerobic fermentation produce ethanol? The answer is yes, but... The alcoholic
content which results from the fermentation of this root beer and found it to be between
0.35 and 0.5%. Comparing this to the 6% in many beers, it would require a person to
drink 1-5 gallons of this root beer to be equivalent to one 12 ounce alcoholic drink. I
would call this amount of alcohol negligible, but for persons with metabolic problems
who cannot metabolize alcohol properly, or religious prohibition against any
alcohol, consumption should be limited or avoided. However, there are many high school
biology labs that have made this beverage without any problems.
Fermentation is used to make a variety of food products, including the making of wine,
bread, cheese, sauerkraut, and baked goods. It is the carbon dioxide produced by the
yeasts that give root beer its "fizz." This fizz is produced in store bought root beer by a
carbonation machine that forces carbon dioxide into the root beer mixture, without the aid
of our little yeast friends.
Materials (All materials should be clean materials used for food preparation)
2-Liter, clean plastic bottles
Funnel
Bottled spring water (or tap water left out for 24 hours)
Dry baker’s yeast
Root beer extract
Sugar
Electronic Balance
Weighing Boats/Paper
Plastic Spoons
25-mL Graduated Cylinder
P a g e | 26
Procedure
1. Gather the materials.
2. With a dry funnel, add in sequence: 200 g of table sugar (You can adjust the amount
to achieve the desired sweetness (no more than 300 g.)
3. Add: 0.8 g powdered baker's yeast. You can see the yeast granules on top of the
sugar. Do not alter the amount of yeast.
4. Shake to distribute the yeast grains into the sugar.
6. Add any other ingredients you feel necessary to create the ultimate root beer.
7. Add with a dry funnel: 15 mL of root beer extract (Zatarain's
or Hires, etc)
8. The extract sticks to the sugar which will help dissolve the
extract in the next steps.
9. Half fill the bottle with bottled spring water. If you are using
tap water, allow the water to sit for 24 hours to allow the
chlorine to dissipate. Rinse in the extract which sticks to the
tablespoon and funnel. Swirl to dissolve the ingredients on
top of the dry sugar.
10. Fill to the neck of the bottle with fresh cool tap water, leaving
about an inch of head space, securely screw cap down to seal. Invert repeatedly to
thoroughly dissolve the contents.
11. Place at room temperature for 24 hours or until the bottle feels hard to a
forceful squeeze. NOTE: Do not leave the finished root beer in a warm
place once the bottle feels hard. After a couple weeks or so at room
temperature, especially in the summer when the temperature is high, enough
pressure may build up to explode the bottle! There is no danger of this if the
finished root beer is refrigerated.
12. Move to a cool place (below 65°F). Refrigerate overnight to thoroughly chill
before serving. Crack the lid of the thoroughly chilled root beer just a little
to release the pressure slowly. NOTE: There will be a sediment of yeast at
the bottom of the bottle, so that the last bit of root beer will be turbid.
Decant carefully if you wish to avoid this sediment.
Discussion
1. After 24 hours, observe your root beer bottle. What has happened? Why?
2. What is alcoholic fermentation? What happens during this process?
3. What factors do you think might affect the rate of fermentation? (Name at least three.
4. How did your root beer taste compared to other groups? Would you do anything
differently if you were to make homemade root beer again? Explain.
P a g e | 27
Case Studies - Trophic Levels
Introduction
One scenario will be introduced (at a time) to the class by the teacher. Each student
group (consisting of 4 students) will present their consensus on the scenario, explaining
the science and bias behind their group decision. Groups are meant to have different
solutions and viewpoints.
Each group of 4 students will represent one of the viewpoints listed below. The
groupings are as follows:
Farmers/gardening enthusiasts Parents of kids and pet owners
Police officers/Firemen/EMT Animal control personnel
Scientists/Environmentalists Senior citizens
Scenario #1:
In Mt. Lebanon, many citizens are concerned about the
overabundant deer population. The deer are eating gardens and
shrubbery. The deer numbers have been increasing over the past
decade. Many are unhealthy and there are increased automobile
accidents. In order to keep them under control, someone proposed
introducing predators, such as tigers, to Mt. Lebanon. However,
city council needs voter support to secure funding for this. What
are some of the concerns and potential solutions to the deer
problem?
Scenario #2:
Some people dream of genetically reincarnating extinct species
(Dinosaurs, Wooly Mammoths, Asian Oxen, Gaurs, and Saber Tooth
Tigers). Ideas like sperm freezing or digging up preserved animals that
still contain DNA may make this a reality. Some suggest using
currently living animals as the surrogate mothers. What are the
benefits and concerns about bringing back extinct species?
Scenario #3:
Many farmers and gardening enthusiasts have their vegetation threatened by
spider mites, aphids, leaf miners, and beetles. To stop these insects from
eating the leaves off of their plants, they want to introduce lady bugs to eat
these insects instead of spraying pesticides. Is the introduction of a predator
a better option than pesticides? What are the benefits and concerns?
Scenario #4:
Some groups want to use 50% of current corn crops for creation of
biofuels (to be used in powering vehicles and for heating). Do you
think that biofuels are a viable energy source? What are the
benefits and concerns?
P a g e | 28
Scenario #5:
If the climate of an area changes (such as due to global warming), how
will that affect the energy and matter flow of the ecosystem? For
example, polar bear habitats are shrinking, putting them at risk of
extinction. Savannahs and grasslands are becoming deserts. What are
some of the concerns and potential solutions to climate change and its
effects?
Scenario #6:
Pymatuning Lake is a popular lake north of Pittsburgh for tourists.
Among other outdoor activities, tourists can feed the carp at the
spillway between Pymatuning Lake and Sanctuary Lake. The state is
banning the feeding of bread to the overpopulated carp in order to
reduce the amount of nutrient input into the lake, such as phosphates
and nitrates, which have resulted in increased aquatic plant growth. Visitors will have to
purchase fish food, primarily made of ground corn, in place of using bread. What are
some of the concerns with the proposal? What alternative solutions are there?
Scenario #7:
Pennsylvania Game Commission issues a specified number of hunting
permits for various animals each year. Why do they pick certain
species? Why do they limit the number of permits? For example, it is
quite rare to see a black bear in the South Hills. However, citizens are
still issued permits for hunting bear. Why? Also, which animals in
food webs/ chains should be permitted to be hunted (if any)?
P a g e | 29
How Do Cell Membranes Regulate Transport?
Part I. How do concentrations of solute inside a cell affect the rate and direction of
osmosis?
Objective
Determine how the concentration of solute within a cell affects the rate and
direction of osmosis
Materials
5 - 250ml beakers 5 dialysis tubes String
Electronic Balances Distilled Water 20% Sucrose Solution
40% Sucrose Solution 60% Sucrose Solution
Procedure
1. Obtain 5 beakers to represent the cellular environments and 5 dialysis tubes to
represent cells.
2. Set up the beakers and dialysis tubes as according to the table below:
Beaker Dialysis Tube
Distilled Water Distilled Water
Distilled Water 20% Sucrose
Distilled Water 40 % Sucrose
Distilled Water 60% Sucrose
20% Sucrose Distilled Water
**Sucrose cannot diffuse through the dialysis tube
3. To create your model cells:
a. Obtain a piece of pre-soaked dialysis tubing. Tie one tight knot in one end
of the tubing. Leave the other end open.
b. Add the appropriate substances into the tubing. Make sure the bag is
moist. You may need to rub the untied end between your fingers to open
it.
c. Close, gently press out air bubbles, and knot the open end of each bag.
Make sure to leave room in your bag for growth. Remember, “cells” may
gain or lose mass! Do not mix up your bags. You may wish to use a
numbered paper towel for each setup.
4. Measure and record the initial mass of each bag.
5. After placing the cells in their environments, run your experiment for 30 minutes
and record your final mass.
6. Determine the percent mass change in a half hour for each “cell”.
a. % mass change = (final mass - initial mass)/initial mass x 100
7. You may set up Part II concurrently with Part I. Do not totally abandon
Part I if you are taking regular measurements.
P a g e | 30
Part II. How large are the pores of a selectively permeable membrane?
Objectives
Determine the size of the pores of a selectively permeable membrane
Observe diffusion of different substances using indicators
Materials
1 - 250ml beaker 1 dialysis tube String
Electronic Balances Distilled Water Glucose
Tes-Tape (Glucose) Starch Solution Iodine
Procedure
1. Obtain 1 beaker to represent the cellular environment and 1 dialysis tube to
represent a cell.
2. You have available 3 different sized molecules – Glucose, Iodine, and Starch.
You also have access to a glucose test.
3. Design an experimental setup, using the indicators (iodine and glucose test paper)
to show if the different molecules can pass through the membrane. Have you
teacher approve your design.
4. Create your cell model using the procedure from Part I.
5. After placing the cell in its environment, run your experiment for at least 10
minutes.
6. Use the data table to record your initial and final observations.
Data
Distilled Water Distilled Water Distilled Water Distilled Water 20% Sucrose
Part I Beaker/Distilled Beaker/20% Beaker/40% Beaker/60% Beaker/Distilled
Water Cell Sucrose Cell Sucrose Cell Sucrose Cell Water Cell
Initial mass
Mass after 30 min.
Percent Mass
Change
Total Mass Change = Final Mass - Initial Mass
Percent Mass Change = (Total Mass Change/Initial Mass) x 100
Part II Initial Observation Final Observation Did the molecules
move through the
Cell Beaker Cell Beaker membrane?
Iodine
Glucose
Starch
P a g e | 31
Results and Discussion
Use the following questions to help you summarize each experiment.
Part I:
Was there correlation between concentration and rate of osmosis? Was there
correlation between concentration and direction of osmosis? How do you know?
Create a graph to show your data.
Part II:
Explain your reasoning for the movement or lack of movement of each of the
molecules. What evidence do you have? Are the “cells” selectively permeable?
Can you determine the size of the pores in the bags?
Application
1. Look at the picture below to answer questions a, b, c, and d.
a. Which substance(s) will rapidly enter the cell?
b. Which will rapidly leave the cell?
c. Which will neither enter nor leave the cell? Explain.
2. Sucrose cannot pass through the membrane. Based on what you learned in Part I,
what would you expect to happen to the “cell’s” mass if:
a. you place a “cell” of 40% sucrose into a cup with 20% sucrose?
b. you place a “cell” of 40% sucrose into a cup with 40% sucrose?
c. you place a “cell” of 40% sucrose into a cup with 60% sucrose?
3. An animal cell is placed in an environment that contains a higher concentration of
water than the cell itself. This type of environment is called a hypotonic environment.
What would happen to the animal cell in terms of water movement?
4. A plant cell is placed in an environment that contains a lesser concentration of water
than the cell itself. This type of environment is called a hypertonic environment. What
would happen to the plant cell in terms of water movement?
P a g e | 32
What environmental factors affect xylem transport in plants?
Introduction
One of the reasons that even wet summers can still end in drought is the
efficiency of plants at moving water from the ground to their upper
reaches where it evaporates from the surface of the foliage. The process is
called transpiration and it's essential for moving water to all parts of
plants, even to the tops of the tallest trees. Celery, a vascular plant, has special tubes,
called xylem, to take up water.
You can imagine with the tallest trees that each water-carrying xylem contains a
continuous, thin column of water over a hundred feet in length and reaching from the
roots to the uppermost leaves. The effect of evaporation at the top of the tree literally
pulls this column of water up the tree. The ability of these thin columns of water to be
pulled in this way – without breaking – is attributed to the cohesive forces between the
water molecules in the liquid; this is called capillary action.
Weather is a stimulus that affects plant transpiration. For example, the process of
transpiration is accelerated by evaporation from the celery leaves. Other environmental
factors also affect the rate of transpiration. You will investigate these factors.
Objective
Determine how different environmental factors affect xylem transport in celery.
Materials
Tub of water Red and Blue Food Coloring
Each group of students will need the following:
Gooseneck lamp Four 125mL flasks Four Stalks of celery
Metric ruler China marker Razor blade
Optional materials:
Salt Sugar Vinegar
Corn Syrup Table fan Hair Dryer
Hot plate Ice Cubes
Procedure
1. Determine three variables you wish to test. Remember to also set up a control as your
fourth setup. You must obtain the basic set of materials for each group, as well as any
other materials you will need.
Consider the following variables: Chemical composition, viscosity, pH, light,
wind, temperature, and foliage
2. Using a razor blade, cut four stalks of celery off while they are submerged underwater.
It is important to do this underwater to ensure that no air enters the xylem.
P a g e | 33
3. Immediately transfer the stalks to the four flasks containing the appropriate dye and
solution (if necessary). Make sure each flask is labeled for each variable. Determine the
length of time to run the experiment and begin timing.
Results
Create a data table to record any information that you may collect. You must also present
your data graphically.
Discussion
1. Explain how each setup is representative of an environment or scenario. Explain
what materials you used to simulate that environment.
2. How does transport in each compare to the control?
3. How do different environmental factors affect xylem transport in celery? Be sure to
explain your reasoning.
4. Give real life examples of how plants are able to survive in environments similar to
what you tested. What adaptations do plants have?
P a g e | 34
What are the effects of exercise on CO2 output and heart rate?
Objectives
Determine the effect of exercise on CO2 output and heart rate
Determine the effect of different exercises on CO2 output and heart rate
Materials (per group)
400-600 mL 0.004% Bromthymol blue solution
2 – 500 mL Ehrlenmyer flasks
1 Solid #7 Rubber Stopper
Glass stirring rod
Drinking straw
100 mL Graduated cylinder
4% ammonia dropper bottle
Clock or stop watch with second hand
Vernier Equipment with Heart Rate Monitor
Procedures
After each part of this Investigation, rest and allow your heart rate and breathing rate to
return to normal. CAUTlON: If at any time during this investigation you feel faint or
dizzy sit down and immediately call your teacher.
Experimental Requirements
You must test at least two experimental treatments
You must have a control
You must have a minimum of three replicates per treatment
Follow procedures A and B when appropriate
A. Procedure to measuring CO2 output using bromthymol blue
1. Pour 100 mL of bromthymol blue solution into your flask.
2. Have one member of your group use a drinking straw to breathe out normally into
the bromthymol blue solution for exactly one minute. CAUTION: Be careful not
to suck the solution into your mouth. The bromthymol blue solution should turn a
pale yellow color at the end of one minute.
3. With a medicine dropper, add 1 drop of ammonia to the flask and stir once with a
glass stirring rod.
4. Continue to add ammonia one drop at a time. Count each drop and stir once
between drops until the solution turns blue. In a data table, record the total
number of drops of ammonia needed to turn the solution blue.
5. Replenish your solution for each trial.
P a g e | 35
B. Procedure for using a hand-grip heart rate monitor
1. Grasp the handles of the Hand-Grip Heart Rate
Monitor. Place the fingertips of each hand on the
reference areas of the handles (see Figure 1).
2. The left hand grip and the receiver are both marked
with an alignment arrow. When collecting data, be sure
that the arrow labels on each of these devices are in
alignment (see Figure 2) and that they are not too far
apart. The reception range of the plug-in receiver is
80–100 cm, or ~3 feet. Figure 1 Figure 2
3. Prepare the computer for data collection by opening
the file “27 Heart Rate & Fitness” from the Biology with Vernier folder of Logger
Pro.
4. Click to begin monitoring heart rate.
5. Click when you have determined that the equipment is operating properly.
Results
Construct appropriate data tables
Graphical representation
Discussion
1. What does the color change of bromthymol blue represent?
2. Is there an effect of exercise on CO2 output and heart rate? If so, what is the
effect and why does it happen?
3. Is there relationship between CO2 output and heart rate? If so, what is the
relationship and why is there one?
4. What are the effects of different forms of exercise on CO2 output and heart rate?
P a g e | 36
What Can You Learn By Testing Urine?
Introduction
All organisms produce wastes. These waste materials must be removed so that
the organism is not poisoned by its own metabolism. In humans, urine is the fluid
produced by the kidneys as they remove waste chemicals from the blood. Urine is made
up primarily of water, with some salts and organic materials dissolved in it. The
concentration of each of these substances varies with a person’s health, diet, and degree
of activity.
By testing the chemical composition of urine, doctors can learn much about the
general health of an individual. Urinary tract infections, kidney malfunction, drug abuse,
diabetes, and liver disease are just some of the medical problems that can be diagnosed
through urinalysis. Urinalysis involves the physical, chemical, and visual examination
of a urine sample.
Objectives
Perform several tests to detect substances in a sample of artificial urine
Determine the contents of an artificial sample of unknown composition
Problem
What can urine testing tell you about a person’s health?
Materials (per group)
Urine sample without glucose Urine sample with glucose
Urine sample without chloride Urine sample with chloride
Urine sample without phosphate Urine sample with phosphate
Urine sample without albumin Urine sample with albumin
0.1 M Silver nitrate (AgNO3) 0.1 M Barium chloride (BaCl2)
5 test tubes Glass-marking pencil
Test tube rack Test tube holder
10 mL graduated cylinder Hot plate
400 mL beaker Benedict’s solution
Biuret’s solution
Safety
Put on a laboratory apron and safety goggles. Handle glassware carefully. Use
extreme care when working with heated equipment or materials to avoid burns.
Laboratory chemicals may irritate the skin or cause staining of the skin or clothing.
Never touch or taste any chemical unless instructed to do so. Discard all solutions as
indicated by your teacher.
P a g e | 37
Procedures
Part A: Testing for Glucose
1. Use a 600 mL beaker and hot plate to prepare a hot water bath.
2. Place two test tubes in a test tube rack. Label one as “experimental” and one as the
“control.”
3. Add 5 ml of urine with glucose to the correct tube. Add 5 ml of control urine to the
other tube.
4. Add 5 drops of Benedict’s solution to both test tubes. Record the pre-heated color of
the test tubes in the data section.
5. Place both test tubes in the hot water bath for 3 minutes then remove the test tubes
with a test tube holder. Place the test tubes in the test tube rack.
6. Record any color changes in the test tubes in the data section.
7. Dispose of the solutions in the sink with plenty of water. Wash the tubes thoroughly.
Part B: Testing for Albumin
1. Place two test tubes in a test tube rack. Label one as “experimental” and one as the
“control.”
2. Add 5 ml of urine with albumin to the correct tube. Add 5 ml of control urine to the
other tube.
3. Add 5 drops of Buiret’s solution to both test tubes.
4. Record any color changes in the test tubes in the data section.
5. Dispose of the solutions in the sink with plenty of water. Wash the tubes thoroughly.
Part C. Testing for Chloride (2-tests)
Silver Nitrate Test
1. Place 2 test tubes in a test tube rack. Label one as “experimental” and one as
“control.”
2. Add 5 ml of urine with chloride to the correct tube and 5 ml of control urine to the
other tube.
3. Add 3 drops of Silver Nitrate (AgNO3) to both tubes. Observe the top surface and
overall color of the liquid in each test tube. Record your observations in the data
section of the lab.
4. Dispose solutions in waste beaker labeled “Silver Waste”. Do not pour these
solutions down the sink. Wash the tubes thoroughly.
Barium Chloride Test
1. Place 2 test tubes in a test tube rack. Label one as “experimental” and one as
“control.”
2. Add 5 ml of urine with chloride to the correct tube and 5 ml of control urine to the
other tube.
3. Add 3 drops of Barium Chloride (BaCl2) to both tubes. Observe the top surface and
overall color of the liquid in each test tube. Record your observations in the data
section of the lab.
4. Dispose solutions in waste beaker labeled “Barium Waste”. Do not pour these
solutions down the sink. Wash the tubes thoroughly.
P a g e | 38
Part D. Testing for Phosphate (2-tests)
Silver Nitrate Test
1. Repeat the methods for the silver nitrate test from Part C.
Barium Chloride Test
1. Repeat the methods for the barium chloride test from Part C.
Part E. Testing an Unknown Urine Sample
1. Put 4 test tubes in a test tube rack. Label one test tube for the glucose test, one for the
albumin test, and 2 for the chloride/ phosphate test.
2. Fill each test tube with 5 ml of unknown urine.
3. Perform each of the tests in section A-C in the lab to determine which substances are
in the unknown urine. The test for part D is the same as part C so you do not need to
repeat it.
4. Record your findings in the data section of the lab.
5. Dispose of the solutions accordingly and remove the tape from the test tubes.
6. Thoroughly wash the test tubes and return them to their original location.
Results
Data Table 1: Glucose Test
Substance Color Before Heating Color After Heating
Glucose Urine
Control
Data Table 2: Chloride Test
Substance Color before Color after Color before Color after
adding adding adding BaCl2 adding
AgNO3 AgNO3 BaCl2
Chloride Urine
Control
Chloride Urine
Control
P a g e | 39
Data Table 3: Phosphate Test
Substance Color before Color after Color before Color after
adding adding adding BaCl2 adding BaCl2
AgNO3 AgNO3
Phosphate Urine
Control
Phosphate Urine
Control
Data Table 4: Albumin Test
Substance Color Before Biuret’s Color After Biuret’s Solution
Solution
Albumin Urine
Control
Data Table 5: Unknown Urine Sample
Test Color After Test Present or Absent?
Glucose
Albumin
Chloride
Phosphate
Discussion
1. Which substance(s) did you find in your unknown urine sample? Do you think this
sample came from a healthy person or sick person? Explain your answer.
2. a) What is diabetes? Explain the difference between hypoglycemic and
hyperglycemic.
P a g e | 40
b) If you add Benedict’s solution to a urine sample from a person who has diabetes
and heat it, what color would you expect the heated sample to be? Explain your
answer by relating it back to your data table and the previous question and base your
response on what chemical(s) you expect to be in the urine.
3. While a blood sample contains glucose, phosphate, albumin, and chloride molecules,
a normal urine sample contains only phosphate and chloride molecules. Why aren’t
glucose and albumin normally found in urine?
4. If a doctor finds high levels of protein in a patient’s urine sample, the doctor will
probably test the patient’s urine several times over a week before drawing any
conclusions. What might be the reason for this?
5. Why can some chemicals be detected in your urine a month after taking them into
your body?
6. Explain sources of error that may have led you to get inaccurate results.
7. What can urine testing tell you about a person’s health? Provide at least three
examples to support your claim.
P a g e | 41
Which antibiotic or disinfectant is best at controlling E. coli growth?
Objective
Determine the effects of antibiotics and disinfectants on E. coli growth
Materials (per group)
Sharpie Bunsen Burner Flint Striker or matches
Sterile cotton swab Sterile paper disks Forceps
Metric ruler Scotch tape E. Coli culture
Sterile nutrient agar plate Various antibiotics Various disinfectants
Procedures
Part A: Inoculating the Sterile Nutrient Agar Plate
1. Label the 4 quadrants on the bottom of the sterile nutrient agar plate using a
Sharpie. See the associated illustration. Note: place the numbers near the edges
of the dish so that we can easily see what is happening in each quadrant.
2. Use a sterile swab and obtain a culture of E. Coli. Note: Do not put the cap of
the container on the desk when obtaining the culture.
3. Slightly open the sterile agar plate and streak the plate in one direction as you
move the swab back and forth. Then, turn the plate 90o and streak the plate in the
other direction. See the illustration to the right.
4. Hold the tip of the cotton swab over a flame until it catches fire and then rinse
it with water. Place the swab in the appropriate disposal container.
Part B: Controlling the Spread of E. Coli with Disinfectants and Antibiotics
1. Examine your agar plate. You should see streaks of bacteria covering the
surface of the agar.
2. Light the Bunsen burner and sterilize the forceps.
3. Select 2 disinfectants, 1 antibiotic, and distilled water as the substances that
you will test.
4. Obtain a sterile disk and dip it into the container containing one of the
disinfectants or distilled water. Note: The antibiotics already come on sterile disks. You do not need to get
a sterile disk when gathering your antibiotic.
5. Shake the excess liquid off of the disk. Slightly open the sterile agar plate and place the disk in the
center of the appropriate quadrant. Give it a gentle press so that it stays in place. Try not to crack the agar.
6. Repeat steps 2-4 when you place the other disks on the plate.
7. Seal the entire perimeter of the plate with tape. Write your name(s) on the side of the dish as well.
8. Place the nutrient agar dishes in an incubator set at 37 oC overnight and examine the results tomorrow.
9. Be sure to wash your lab area with a disinfectant. Wash your hands thoroughly with soap and water.
Part C: Measuring the Zone of Inhibition
1. Remove the plates from the incubator and measure the zone of inhibition for each of the 4 disks placed
in the bacteria. If no zone is apparent, record the measurement as zero.
2. Collect the data from the class and determine the average zones of inhibition for each of the products
used.
3. Dispose of the Petri dish in the appropriate trash container.
4. Be sure to wash your lab area with a disinfectant. Wash your hands thoroughly with soap and water.
P a g e | 42
Results
ZONES OF INHIBITION:
Effects of Disinfectants and Antibiotics on E. coli
Group 1 Group 2 Group 3 Group 4 AVERAGE
Disinfectant
(mm) (mm) (mm) (mm) (mm)
1.
2.
3.
4.
5.
6.
7.
8.
Group 1 Group 2 Group 3 Group 4 AVERAGE
Antibiotic
(mm) (mm) (mm) (mm) (mm)
1.
2.
3.
4.
Group 1 Group 2 Group 3 Group 4 AVERAGE
Distilled Water
(mm) (mm) (mm) (mm) (mm)
Discussion
1. Why is it important to use sterile techniques while inoculating the agar plates?
2. Which disinfectant or antibiotic was most effective in removing the bacteria?
3. If a disinfectant is the most effective, why aren’t they used to treat human bacterial infections?
4. How can you relate this lab to your own life? Discuss what the results mean for antibiotic use,
disinfectant use, and the evolution of bacteria.
P a g e | 43
How do germinating seeds respond to environmental changes?
Cotyledon
Shoots
Roots Root Hairs
Objective
To investigate how germinating seeds respond to environmental changes
Materials (per group)
2 Petri dishes Scissors
Glass marking pencils Nonabsorbent cotton
Heavy blotting paper Transparent tape
Modeling clay
8 soaked corn grains (or other large seed such as radish seeds)
Procedure
This is simply a sample procedure to investigate phototropism.
To investigate thigmotropism, the students can apply small pieces of tape to the stems of the
germinating plants.
For gravitropism, the petri dishes can be inverted.
For a control, the teacher can construct a few petri dishes so that later the students can compare
their results.
1. One day before the investigation, soak the seeds in water.
2. Place 4 water soaked corn grains in the bottom half of a Petri dish. Place one at the top, one at the
bottom, and one on both the left and right side. Arrange them so that the pointed portion of the seed
faces the center of the dish.
3. Cut a piece of blotting paper slightly larger than the bottom of the Petri dish, wet it thoroughly, and fit it
snugly over the grains.
4. Fill the remaining space with wads of nonabsorbent cotton to a depth slightly greater than the thickness
of the grains. Do not use too much cotton.
5. Hold the dish on its edge, and observe the grains through the bottom. If they do not stay in place, then
pack them with more cotton.
6. When the grains are secure in the dish, seal the two halves of the Petri dish together with tape.
7. Rotate the dish until one of the grains is at the top. With a glass marking pencil, write an “A” on the
Petri dish, then proceeding clockwise, label the other grains B, C, and D. Also label the Petri dish with
one of the lab member’s last name.
8. Use modeling clay to support the dish on its edge with grain “A” at the top. Place the dish into dim light.
9. Be sure to wash your hands and workstation, and clean up any extra materials.
10. You must determine how you will collect data. When the grains begin to germinate, include sketches
and measurements every day for 5 days, showing the direction in which the root and shoot grow from
each grain.
P a g e | 44
Sensory Receptors Lab Observations
In this lab, you will be guided through a series of tasks that have to do with your senses.
You will need the help of your lab partner to perform many of these tasks, so make sure
you work together.
For each task or station, note your observations and your scientific explanations or
hypotheses that may explain these observations.
Pupil Reflexes:
Observations: (include drawings) Explanations:
Visual Accommodation
Observations: Explanations:
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Blind Spot
Observations: Explanations:
Binocular Vision
Observations: (include drawings) Explanations:
Tube:
Fingers:
Eye Dominance
Observations: Explanations:
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Optical Illusions
Observations: Explanations:
Cars:
Animals:
Squares and Lines:
Hat:
Circles:
P a g e | 47
Retaining Images
Observations: Explanations:
Auditory Acuity
Observations: Explanations:
Sound Localization
Observations: Explanations:
P a g e | 48
The Sense of Smell
Observations: Explanations:
The Sense of Taste
Observations: Explanations:
The Sensation of the Skin
Observations: Explanations:
Discussion: Using at least three different examples from your investigation, explain how
your different senses work together to allow us to respond to stimuli? Include real life
situations where these phenomena are applicable. Examples may include things you do
on a day to day basis.
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Testing the Nervous System
Objectives
The purpose of this lab is for each group to answer a question based on an application of
the nervous system. Some possible questions that can be asked:
Do different variables affect reflex time?
Can you control your heart rate consciously?
Does short-term memory differ amongst individuals?
Methods
1. You and your group will either choose a question from this list or develop a question
on you own. Once you have done so, you will indicate to your teacher the question that
you have chosen. If you are developing you own question, you must have it approved.
2. Once you have chosen a question, you must first develop a hypothesis based on the
question. This will be a prediction based on your question.
3. Next, you will develop an experimental procedure to test you question. This
procedure must be redundant enough that it will provide evidence to support your
conclusions, so several trials will be necessary. Also, as you develop your experiment,
you must also develop ways to collect and analyze data. You will need several data
tables to support your conclusions.
*You may need to test individuals who are not in your group, so as to have a full data set.
4. Once you have developed your experiment, please have it approved by your teacher to
make sure that you have all of the materials that you need.
5. The running of the experiment will come next and allow you to test you hypothesis.
Please make sure that all of the data that you record is done in an orderly fashion as to be
read later.
6. Once you have concluded your experiment, the most important part of the lab will be
to present you conclusions. You will present whether you accept or reject your
hypothesis based on your data. You must discuss your experimentation and support your
claim with sufficient data.
P a g e | 50
Investigating Invertebrate Behavior
Objectives
Study basic invertebrate anatomy
Safely handle invertebrates
Design an experiment to study invertebrate behavior
Materials
Small paintbrush Spoon Ruler
Petri dish Stereoscopic dissecting microscope
Scissors Tape
Optional materials
50 ml beaker with water Paper towels Plain white paper
Plastic Bin Assorted rocks Fragrances
Food sources
Organisms
Pill bugs Crayfish Snails
Worms Spiders Various insects
Procedure
I. General Observations
Work with at least two organisms of the species being investigated to answer the
following questions.
1. Does your organism have any appendages? If so, what are their functions?
2. Does your organism have a hydrostatic skeleton, an endoskeleton, or an
exoskeleton? Explain how you know.
3. What does the organism do when it comes to an edge where there is a drop off?
4. Can the organism climb on steep smooth surfaces like the edges of the Petri dish?
Can it climb on rough surfaces like your arm?
5. How does your organism seem to sense its environment?
6. Can you tell the difference in males and females? Explain.
P a g e | 51
7. Does your organism exhibit dominance behaviors? Explain.
8. How does your organism respire?
9. What are some stimuli your organism seems to respond to?
10. Describe how your organism moves.
11. How fast does your organism move? Make an X in the center of the copy paper.
Place the organism on the center of the X. Let it go and record the time in seconds
that it takes to run off the paper. Place another X where it left the paper. Measure the
distance between the 2 X’s in centimeters. Calculate the speed of the organism in
cm/sec.
12. How does your organism respond when disturbed?
13. Do you have all of the same species? How do you know?
II. Microscopic Observations using a Dissecting Stereoscope
When you make a sketch of the organism, don't just draw an oval with a few squiggly
legs - you are expected to do a scientific illustration similar to the sketch of an earthworm
below.
Include these items in your sketch and be sure to label them on your drawing.
Determine the relative proportions (length, width, height as well as lengths of
body parts)
Count the number of body segments, antennae, and appendages
Locate and label the body parts
Hair locations
Does it have eyes? How many? Compound or simple?
Examine the ventral (underside) surface.
P a g e | 52
Make your sketch in the space provided:
III. Designing and Reporting an Investigation
1. Brainstorm with your partner about possible behaviors you would like to investigate.
2. Select one problem you would like to investigate.
3. Write a hypothesis that relates to your problem. Here is a good and bad example:
Poor: I think Pill bugs will move toward the wet side of a choice chamber.
Better: If Pill bugs prefer a moist environment, then when they are randomly placed
on both sides of a wet/dry choice chamber and allowed to move about freely for 10
minutes, most will be found on the wet side.
4. Identify the variable you will manipulate (independent variable), the variables that
will be controlled or stay the same, and one variable will be the one that you will
measure (dependent variable).
P a g e | 53
Methods
For the experiments you design, you will need to create behavior to test the organisms’
reactions. Each basic chamber will consist of two sides, each side having a different
environment, plus a tube that connects the chambers so that the organisms can move from
one place to the other. The materials are up to you.
Example One group measured the response to moisture over 10 minutes. For their
procedure, they set up their behavior chamber so that they had one side moist and one
side dry (using paper towels). They transferred 5 isopods to each side of the chamber
(total of 10). They counted and recorded the number of animals on each side of the
chamber every 30 seconds for ten minutes, using a table similar to the following.
Results - Example
Time (min:sec) # in Wet # in Dry Other Notes
0:00
0:30
1:00
1:30
Some other suggestions for experimentation may include, but are not limited to…
Factor Materials (suggested)
Temperature cold pack, warm pack
lamps, flashlights, dark construction paper, aluminum
Light
foil
pH low pH (HCl), high pH (NaOH)
Substrate (surface) soil, sand, sandpaper, bark, paper, cedar chips, gravel
Odor Ammonia
Presence of other organisms spider, worm, cricket
Food apple, potato, fish food, lunchmeat
Discussion
Follow the lab report requirements for a full discussion of your findings.
P a g e | 54
anana DNA Extraction
Introduction
Bananas are good sources of DNA. You will break open the cells and
then separate the DNA from the remaining cell parts. Next time you
eat bananas, perhaps you’ll be thinking about the large amount of DNA
that you’re eating.
Prediction
What do you think the DNA that you extract will look like?
Materials
Table salt Dishwashing detergent Meat tenderizer
Distilled water Isopropyl alcohol Bananas
Self-sealing baggie Wooden coffee stirrer Test tube
Test tube rack Filter paper Funnel
Small scoop Teaspoon scoop 25 ml graduated cylinder
Microcentrifuge tube (optional) Methylene blue (optional)
Procedures
1. Place a third of a banana into a baggie, press the air out, seal it, and mash for 2
minutes.
2. Add a teaspoon of salt and 20 ml of water to the bananas and repeat the previous step
for 1 minute.
3. Pour the mixture through the filtration apparatus, collecting it into a test tube.
4. Add approximately as much dishwashing detergent as filtrate to the test tube. No more
than 5 ml are required. The test tube should be about half full after this step.
5. Add a small scoop of meat tenderizer.
6. Mix gently for about 2 minutes by covering and inverting the test tube and also
swirling it. Make sure not to be rough or you will break up the DNA molecules.
7. Very slowly add several milliliters of isopropyl alcohol to the extract by pouring it
gently down the side of the test tube. The test tube should be about 2/3 full after this
step. Do not stir it.
8. Alcohol will be floating on top of the mixture. Wait a few minutes and stringy globs
will appear in the alcohol. That is DNA!
9. Dip the wooden stirrer through the alcohol, into the DNA/buffer solution. Gently twirl
the stick just below the boundary of the two layers. After a minute of twirling, slowly
pull the stick up out of the test tube.
10. Make observations.
11. You may add methylene blue to the rest of the test tube. What does this do?
12. If you wish, the DNA can be saved. Obtain a microcentrifuge tube and add some
DNA to it by scraping it into the tube.
P a g e | 55
Discussion
1. List 5 things available to you that you might use for a DNA source besides bananas.
2. List 5 things that would not be a DNA source.
3. Why did you use detergent in the procedure? What does it do?
4. Which ingredient do you think had the most effect on the amount of DNA you
extracted? Describe an experiment that you could perform to test this.
5. Why is DNA important to living things?
6. Was your prediction correct? Why or why not?
P a g e | 56
During the cell cycle, which stage do onion root cells
spend the most time in?
Objectives
Determine the amount of time onion cells spend in each stage of the cell cycle
Introduction
In some cells, such as human muscle cells and nerve cells, mitosis never occurs. In
plants, this is not true. Plant cells continually undergo mitosis. In this investigation, you
will identify the various stages of the cell cycle and the stage plant root cells spend the
most time undergoing.
Materials (per group)
Textbook Prepared slide of plant mitosis (onion root tip)
Onions Toothpicks Beakers of Water
Microscope Safety goggles Metric ruler
Ethanol-acetic acid Scalpel Forceps
3-50 ml beakers Glass marking pencil Hydrochloric Acid
Clock with second hand 2 glass slides 2 medicine droppers
Toluidine blue Probe Paper towels
Cover slip
Procedure
1. One week to 10 days before the lab, insert toothpicks into an onion bulb and suspend
it in a beaker of water so that the bottom of the bulb is under the water. Allow the
roots to grow to a length of at least 1 cm.
2. One day before the lab, prepare the fixative with 75 ml of ethanol to every 25 ml of
glacial acetic acid. Work only where there is sufficient ventilation, as the fixative is
volatile.
3. Cut a 3 mm piece from the tip of each root and place it in a beaker of the prepared
fixative. Try to do this around noon because of the occurrence of mitosis peaks at
this time (as well as midnight).
4. Try to keep the roots in the fixative for at least 4 hours (but not longer than 48 hours).
The fixation will “stop the action” of the dividing cells and preserve them in their
current state. The acid will soften the plant cell walls to make the “root tip squash”
easier.
5. Label the three 50 ml beakers with the glass marking pencil as follows: fixative, HCl
[use 5 M (18%) Hydrochloric Acid], water. Put on your safety goggles and add 10 ml
each liquid to the appropriately labeled beaker. CAUTION: Because acids can burn
the skin, handle them with care. Place the beaker containing the water aside for now.
6. Using forceps, remove the tips from the fixative and place them in the HCl beaker for
4 minutes.
7. After 4 minutes, use the forceps to remove the root tip from the HCl and place it back
into into the fixative for 4 minutes.
8. After 4 minutes, use the forceps to remove the root tips from the fixative and place
them on a clean glass slide. Holding the root tips with the forceps, use a scalpel and
P a g e | 57
cut off about 1 mm from each root tip. CAUTION: Be careful when using a scalpel.
Discard the remainder of the root.
9. Place the glass slide on a paper towel.
10. Place a few drops of toluidine blue on the root tip. Allow the toluidine blue to remain
on the root tip for 2 minutes. After 2 minutes, use a paper towel and absorb the
excess liquid.
11. Using a clean medicine dropper, place 2 drops of water on the root tip. Cover it with
a cover slip.
12. Place a paper towel over the slide, and with the eraser end of the pencil, gently press
down on the area covered by the cover slip. This will squash the root tip.
CAUTION: Do not press so hard as to break the cover slip or the glass slide.
13. With the microscope, examine the onion root tip under low power to find the cells in
various stages of the cell cycle. (Note: If you cannot clearly distinguish the stages of
the cell cycle, repeat steps 6 through 12 using another root tip.)
14. After you have located the various stages of the cell cycle under low power, switch to
high power. If you have digital access, capture a digital micrograph of cells in each
stage of the cell cycle. If not, draw out a cell in each phase.
15. Next, focus on one area of the root tip at low power. You should be able to see the
various stages of the cell cycle. Print out a digital micrograph of the image if you are
using a computer.
16. Count the total number of cells in each of the 5 phases. Record this information in
the appropriate place in Data Table I. Now add up the results for each phase to get
the total number of cells in the field of view.
17. Now combine data from the other groups and determine the percentage of time spent
in each of the stages of mitosis. To determine the approximate proportion of time a
cell spends in each phase of mitosis, divide the number of cells in each phase by the
total number of cells in the field of view. To convert each decimal to a percent,
multiply by 100. Record this information in the appropriate place in Data Table II.
Results
Data Table I: Individual Group Data
Plant Cell Mitosis:
Phase Number of Cells in Each
Phase
Interphase
Prophase
Metaphase
Anaphase
Telophase
Total number of
cells in field of
view
P a g e | 58
Data Table II: Class Data
Number of Cells in Each Percentage of Cells in
Phase
Phase Each Phase
Interphase
Prophase
Metaphase
Anaphase
Telophase
Total number of
100%
cells investigated
**Be sure to attach your digital images.
Discussion
1. In which phase of the cell cycle is the most time spent? Why?
2. How much time is spent during mitosis (PMAT)? How does this compare to the total
time for the cell cycle?
3. What are plant and animal cells doing when they are not undergoing mitosis?
4. Yeast is capable of undergoing one full cycle in 30 minutes. Using the information
that you obtained from your analysis, how long Yeast spends in each phase?
Interphase
Prophase
Metaphase
Anaphase
Telophase
P a g e | 59
Principles of Genetics
Introduction
Through his careful and detailed studies with garden pea plants, the Austrian
monk and scientist Gregor Mendel determined that heredity is controlled by factors that
are passed from generation to generation with predictable results. Mendel’s experiments
and conclusions led to the formation of several basic genetic principles.
The principle of dominance states that some factors (alleles) are dominant,
whereas others are recessive. The effects of a dominant allele are seen even if it is present
with a contrasting recessive allele. The principle of segregation states that during gamete
(sperm and egg) formation, the alleles for a trait separate, so that each gamete has only
one of the alleles for that trait. The principle of independent assortment states that as
gametes form, the genes for various traits separate independently of one another.
In this exercise, you will construct Punnett squares to observe the principles of
genetics that were based on Mendel’s work. You will also simulate a dihybrid (two-
factor) cross to learn the important role probability plays in the study of genetics.
Objective
To predict the outcome of a dihybrid cross
Materials
plastic cup masking tape scissors
plastic disks (4) marker
Procedures
Part A : Constructing Punnett squares for one-factor and two-factor crosses.
1. Examine Figure 1. The capital letter T is used to represent the dominant allele for
tallness in the stem length for pea plants. The lower case letter t is used to represent the
recessive allele for shortness in stem length for pea plants. Notice the genotypes or gene
combinations that result from the parental (P1) generation cross between a female
purebred tall (TT) pea plant and a male recessive short (tt) pea plant. All of the offspring
that make up the first filial (F1) generation are tall (Tt). Their phenotypes, or visible
characteristics, are all tall.
P a g e | 60
Purebred tall female x Short male
P1 generation Genotype TT x tt
Female gametes
T T
t
Male gametes Tt Tt
t Tt Tt
genotypic ratio = 100% Tt
F1 generation
phenotypic ratio = 100% tall
Figure 1
2. Figure 2 shows the results of a one-factor cross between the offspring from the F1
generation. Observe the genotypic and phenotypic ratios for the second filial generation
(F2). When writing such ratios, the numbers for the dominant genotypes or phenotypes
come first. In this example, ¼ of the offspring are TT, two fourths or ½ are
Tt and ¼ are tt. The genotypic ratio therefore is ¼ : ½ : ¼ or 1 : 2 : 1.
Three fourths of the offspring are tall and one fourth are short so the phenotypic ratio is ¾
: ¼ or 3 : 1.
Hybrid tall female x Hybrid tall male
F1 generation Genotype Tt x Tt
Female gametes
T t
T TT Tt
Male gametes
t Tt tt
genotypic ratio = 1 : 2 : 1
F2 generation
phenotypic ration = 3 : 1
Figure 2
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3. In soybeans, purple flower color is dominant and white flower color is recessive. Let
P represent the dominate allele (purple) and p the recessive allele (white).
4. Predict the possible genotypes of the first filial generation (F1) of offspring by
completing the Punnett square in Data Table 1. Indicate the genotypic and phenotypic
ratios of the F1 generation.
5. In Data Table 2, cross two plants from the F1 generation. Write the appropriate
genotypes for this cross on the lines provided. Predict the probable genotypes of this
cross by completing the Punnett square in Data Table 2.
6. Indicate the genotypic and phenotypic ratios of the F2 generation in Data Table 2.
7. In corn plants, rough seed shape (R) is dominant over smooth seed shape (r) and
yellow seeds (Y) are dominant over white seeds (y). Determine the probable seed shape
and color of the F1 generation of offspring whose parents are heterozygous for the traits
by completing the Punnett square in Date Table 3. Then, fill in Data Table 4.
Observations
Data Table 1
Purebred purple female x White male
P1 generation = PP x pp
Female gametes
Male gametes
Genotypic ratio =
F1 generation
Phenotypic ratio =
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Data Table 2
F1 generation = ________ x _________
Female gametes
Male gametes
Genotypic ratio =
F 2 generation
Phenotypic ratio =
Data Table 3
P1 generation = RrYy x RrYy
Female gametes
RY Ry rY ry
RY
Ry
Male gametes
rY
ry
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Data Table 4
Genotype Genotypic Ratio Phenotype Phenotypic ratio
RRYY
RrYy
RrYY
RRYy
RRyy
Rryy
rrYY
rrYy
rryy
Part B: Simulating a Two-Factor Cross
1. To simulate the two-factor cross discussed in step 7 of Part A, cut 8 pieces of masking
tape just large enough to fit on the plastic disks. Place the tape on both sides of all 4
disks.
2. On one side of two of the disks write R. On the other side of these, disks write r.
Repeat this with the other two disks writing Y on one side and y on the other side.
3. Each labeled disk represents the alleles in the heterozygous plant. Tossing the disks
together represents the crossing of the heterozygous plants.
4. Place the 4 labeled disks into the plastic cup. Holding one hand over the top of the
cup, shake it so that the disks are tossed together in the cup. Then, empty the cup onto the
lab table and record the results of the toss by making tally marks in the appropriate spaces
of Data Table 5.
5. Toss the disks a total of 48 times, recording the results of each toss in Data Table 5
count the tally marks for each phenotypic combination and record these totals in the
appropriate place in the table.
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Data Table 5
Number Number
Total
Expected Expected
Phenotypes Genotypes Toss Results Number
For 16 For 48
observed
Offspring Offspring
RRYY
Rough, yellow RrYy
seeds RRYy
RrYY
Rough, white RRyy
seeds Rryy
Smooth, yellow rrYY
seeds rrYy
Smooth, white
rryy
seeds
Discussion
1. When two homozygous plants with contrasting traits are crossed, what are the
expected genotypes for the offspring?
2. What is the expected genotypic ratio for a one-factor cross of two hybrid organisms?
3. What is the expected phenotypic ratio for a one-factor cross of two hybrid organisms?
4. In your simulated two-factor cross, why might your actual experimental values have
been different from the values you expected?
5. Why is it helpful to conduct a large number of trials when simulating genetic crosses?
P a g e | 65
Application
1. Why would animal or plant breeders need an understanding of genetics?
2. Is it possible for two organisms to have different phenotypes but the same genotype?
Explain your answer.
3. Is it possible for two organisms to have different genotypes but the same phenotype?
Explain your answer.
4. How could a guinea pig breeder determine whether a rough-coated guinea pig is
homozygous or heterozygous for this trait?
5. In dogs, wire hair is due to a dominate gene W. Two wire-hair dogs were mated and
produced a puppy with smooth hair. What were the genotypes of the two parent dogs?
6. Repeat Part B of this activity using a cross between the genotypes RrYy and Rryy.
Construct a Punnett square on a separate sheet of paper to represent your expected results
and calculate the expected genotypic and phenotypic ratios. Tally the results of your 48
tosses and compare your experimental values with the expected values.
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Applying Mendelian Genetics
Meiosis Gamete Production – Demonstrating Crossing-over
Objective
To understand the principles of gamete production through Mendelian Genetics.
Materials
scissors, tape, data table, chromosome handouts, and a portrait sheet
Procedure
1. Find a partner to work with. Opposite sex partners work the best!
2. You are to determine the phenotype characteristics of an offspring through
meiotic gamete production.
3. The table below determines the phenotypes and genotypes for each partner. Each
partner will complete that characteristics information for Data Table I.
Phenotype Characteristics
Skin Color If you have dark hair and dark colored eyes your phenotype is dark skin and
your genotype contains both dominant alleles for the gene- SS. If you have
either light colored eyes OR light hair color, then your phenotype for skin type is
light skin and your genotype is heterozygous-Ss. If you have BOTH light
colored eyes and light colored hair, then you possess a white skin color with a
recessive genotype of ss.
Hair Style If your hair is straight then you are homozygous dominant (HH) and have the
straight phenotype. If your hair is wavy, then you are heterozygous (Hh) with
wavy hair. If your hair is curly, then you are homozygous recessive and have the
genotype hh.
Hair Color If your hair is black, then your color is dark and you are homozygous dominant
(CC). If your hair color is blonde, then you are homozygous recessive (cc) with
light hair. If your hair is somewhat in between, then your phenotype is mixed
color and you carry the alleles Cc.
Eye Color If your eye color is brown then your genotype is EE and your color is brown. If
your color is blue, then you are homozygous recessive and your phenotype is
blue. If your color is green, then your genotype is Ee.
Body If your weight is above 150 lbs, then your phenotype is round and you carry the
Morphology alleles GG. A weight of 125-149 lbs denotes a phenotype of husky and alleles
Gg. A weight less than 125 lbs denotes a phenotype of slim and possesses the
alleles gg.
Sex If you are a male your genotype is XY. Females have the genotype XX.
Face Shape Let your partner be the judge. If you have a round face, then you are
Homozygous dominant (AA) and have the phenotype round. If you have the
phenotype of oval, then your genotype is heterozygous (Aa). If you have the
phenotype of square, then your genotype is aa.
Arm/ Leg If you are 5’10” or larger, then you have the phenotype tall and possess
Length homozygous dominant alleles (TT). If you are 5’4” – 5’9” then you carry the
phenotype of medium height and the alleles Tt. A height of 5’3” or less has the
phenotype of short and alleles tt.
P a g e | 67
4. Each student must complete the lab activity in developing his or her own gametes.
5. The traits for genes 1-4 are found on chromosome pair #1 and the traits for genes
5-8 are found on chromosome pair #2. Write your alleles on the chromosomes as
they appear in the chart.
6. Cut out the sister chromatids and temporarily connect the duplicate and the
original at centromere. Then, form a tetrad by connecting the homologous pairs
together. You should have two tetrads. DO NOT OVERTAPE
THROUGHOUT LAB. YOU WILL TAKE THE CHROMOSOMES
APART SEVERAL TIMES. Use these chromosomes as you work through the
stages of meiosis with the following chart. At the end of the chart you will have
created the sex cells needed for reproduction.
**Go through meiosis I & II using chart**
7. Complete the sketch with a working model of two chromosomes going through
the steps of meiosis I and II found on pages 3 and 4. Use your desktop surface for
the working model. At the conclusion of your sketch and model, you will have 4
gametes (sperm or egg) on your desktop.
8. Using the directions from the meiosis chart, mate the male and female sex cells
together. Write the alleles of the offspring that will be produced in Data Table II.
9. Draw your child that will be produced from your initial characteristics. Be sure to
use colored pencils and write its name on the portrait sheet!
10. You must turn in the data tables and pictures.
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Meiosis I
[As you sketch your model in the circles below, make a working model on your desktop.]
Replicate your 2 chromosomes using the
base chromosome pairs. Make sure that the
Interphase replicated set is identical. There are two
models working, dad and mom. Each
student does their own!
Pair up the homologous chromosomes at the
centromere to form a tetrad . This is called
synapsis. Then illustrate crossing over. Do
Prophase I this by cutting off either 1 or 2 genes on the
crossed over section of each chromosome.
Next, re-tape the genes on the homologous
chromosome.
Metaphase I
Line up the crossed over chromosomes on
the metaphase plate in the center of your
desk.
Anaphase I
Separate the tetrads, showing the tetrads
being pulled to the opposite ends of your cell
(desk).
Telophase I
Now you should have 2 cells, both having 1
set of chromosomes for chromosome 1 and
2.
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Meiosis II
Prophase II During this stage, there is no noticeable
activity. Leave your chromosomes
alone here.
In both cells the chromosomes line up
Metaphase II along the metaphase plate. Show this
on your desk. Keep in mind that you
are still working with 2 different cells.
In each cell, split the sister chromatids
and show them moving to opposite
Anaphase II poles. Make sure that each pole in each
cell contains one chromosome 1 and
one chromosome 2.
Telophase II
Line the 4 gametes (sex cells) up along
your desk. The third one from the left
will be used for reproduction with your
partner’s gamete.
Discussion
1. What is the difference between a chromatid and a tetrad?
2. What is synapsis? What is the only stage that synapsis occurs?
3. What is the significant difference between the development of the sperm and the egg?
4. What are polar bodies?
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Data Table I: Characteristics of Parents
Mom Mom Genotype Dad Phenotype Dad Genotype
Genes Phenotype
1. Skin Type
2. Hair Style
3. Hair Color
4. Eye Color
5. Body
Morphology
6. Sex
7. Face Shape
8. Arm/ Leg
length
Data Table II: Characteristics of Child
Allele from Allele from Genotype of Phenotype of
Genes Mother Father Child Child
1. Skin Type
2. Hair Style
3. Hair Color
4. Eye Color
5. Body
Morphology
6. Sex
7. Face Shape
8. Arm/ Leg
length
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How Can Blood Typing Be Used To Determine Parent-
Offspring Relationships?
Objectives
Simulate blood typing
Use blood typing to solve a parent-offspring relationship case
Materials
2 Spot Plates Test Tube Brush Detergent
Dropper Bottles with:
Recipient Type A
Recipient Type B
Recipient Type AB
Donor Blood Types: A, B, AB & O
Unknown Children and Parent Blood Samples
Introduction
Understanding blood types is important in the transfusion of blood. Fill out this chart
based on what you know about blood types and antigens. Remember, a person can only
receive antigens that they are familiar with.
Blood Types Antigens in Red Can Donate To… Can Receive
Blood Cells From…
A
B
AB
O
1. Which blood type is known as the universal donor? Why?
2. Which blood type is known as the universal acceptor? Why?
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The ABO blood groups are determined from a single gene with three possible alleles: IA,
IB, or i. Since IA and IB are both expressed when they occur together, they are said to be
co-dominant. IA and IB are both dominant over i. Fill in the following chart to illustrate
the genotypes of individuals with each of the four blood types.
Phenotype Genotype
A
_____ _____ or _____ _____
B
_____ _____ or _____ _____
AB
_____ _____
O
_____ _____
In addition to the ABO antigens, there is another antigen on the red blood cells that
determines the success or failure of transfusions. It is the Rh antigen named after the
rhesus monkey in which the antigen was first discovered. People who have the antigen
on their red blood cells are Rh positive (Rh+). People without the antigen are Rh negative
(Rh-). In blood banks the ABO and Rh groups are often expressed together in symbols
such as AB- or O+. The gene for the Rh antigen displays simple dominance, where + is
dominant over -. Fill in this chart to help illustrate the genotypes of different Rh blood
types. Denote each allele as either Rh+ or Rh-.
Phenotypes Genotypes
Rh Positive
_____ _____ OR _____ _____
Rh Negative
_____ _____
Use your knowledge of blood types and genetics to solve the following problem.
1. A man with blood type AB marries a woman with type O blood. What blood types
would you expect to see in their children and in what percentage? Show your work.
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Procedures
Part I: Universal Donors and Recipients – Demonstrating Blood Type Tests
1. Set up the spot plates as instructed. The first row of four people will all have type-A
blood, the second row of four people will all have type-B blood, the third row will
have type-AB, and the fourth will have type-O blood. Place the spot plate on the
chart on this page to aid you in placing blood in each well. Using the dropper bottles,
place 3 drops of type-A (recipient) blood in the first column for the A-recipients.
These represent the recipients with type-A blood.
2. Now fill the other columns with 3 drops of the correct recipient blood (A, B, AB, or
O).
3. Now we are going to perform a blood transfusion to each of the 20 different people.
First add 3 drops of type-A donor blood to the first individuals in rows #1-4. Add 3
drops of type-B donor blood to the 2nd individuals in rows #1-4, and so on. See the
chart for assistance.
4. On the chart below write draw a “smiley” face to show a successful transfusion of
blood. This shows that the recipients and donors are compatible. Draw an unhappy
face to show that the transfusion was not successful and the recipient did not survive.
5. Discard solutions in the sink, wash spot plate with detergent and test tube brush.
Recipients Blood Type
A B AB O
A
B
Donors
AB
O
Part II: Whose baby is it?
On a dark, stormy night in Pittsburgh, four newborn babies were being transferred to the
nursery in a prestigious University Hospital when a power outage occurred. In the
ensuing confusion, one of the new residents inadvertently mixed up the four newborns.
Although embarrassed by the mistake, the responsible resident reported the situation to
the chief resident. You are the lab technician, which received the blood samples taken
from the parents and newborns. Through analysis of the parents and newborn babies’ red
blood cell antigens, it is now up to you to determine the parents of each of the newborns.
The Rh factor is provided to help you. Good luck!!
P a g e | 74
1. Obtain samples from each of the children and parents (3-drops/ well). Use the data
table so you know what goes into each well.
2. At your seat, determine the blood type of the children and parents using additional
wells on your spot plates. Use the dropper bottles of type A, B, and AB recipient
blood types to determine the presence or absence of “A” and “B” antigens. (The Rh
factors are already recorded). Record the blood types in the table below.
3. Discard solutions in the sink and wash the spot plates with detergent and test tube
brush.
Human Blood Groups Data Table
Recipients
Type A Type B Type AB Type O Blood Type
Baby 1
Baby 2
Baby 3
Baby 4
Mr. Brown
Donors
Mrs. Brown
Mr. Gray
Mrs. Gray
Mr. Smith
Mrs. Smith
Mr. Jones
Mrs. Jones
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4. Using the phenotypes of the parents (from the blood samples examined),
determine the possible outcomes for the babies’ alleles. Remember, each parent
has two alleles. For type A and type B parents, assume that they carry the
recessive allele.
Possible Offspring Genotypes
(Show all work for the possible outcomes of the following parents. You may use a
Punnett Square to help)
Mr. & Mrs. Brown Mr. & Mrs. Smith
Mr. & Mrs. Jones Mr. & Mrs. Gray
Fill in the following table using the blood types determined through testing.
Baby Blood Types
Baby Blood Type
Rh Factor (Including Rh)
1 +
2 +
3 -
4 +
P a g e | 76
Parents Offspring
Name Rh Factor Blood Type Possible Rh Possible Blood
Factor(s) Type(s)
Mr. Brown +
Mrs. Brown -
Mr. Gray +
Mrs. Gray -
Mr. Smith -
Mrs. Smith -
Mr. Jones +
Mrs. Jones -
Once you have determined all of the possible outcomes, determine which child belongs to
which set of parents. Record the parents below.
Parent-Offspring Relationships
Child Parents
1
2
3
4
Application
1. Suppose 2 newborn babies were accidentally mixed up in the hospital, and there was
a question of which baby belonged to which of the parents. From the following blood
types, determine which baby belongs to which parents.
Mrs. Schrader Type B+ Mr. Schrader Type AB-
Mrs. Hathy Type B+ Mr. Hathy Type B+
Baby 1 Type O+ Baby 2 Type A+
2. What are the genotypes of each of the six people listed above?
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3. Complete the family tree below and give the genotypes of the following individuals.
A B
A B AB A A O A
A O A A A A O B
B
A B B O
4. What are the possible blood types of children in the following families?
Type-A+ mother, type-A- father
Type-A- mother, type-O- father
Type-B- mother, type-AB- father
Type-AB+ mother, type-AB- father
Type-A+ mother, type-B+ father
Discussion
1. Write a paragraph explaining the importance of blood typing. In what ways is blood
typing useful? What are the limitations of blood typing? What is your blood type?
P a g e | 78
Karyotyping
Introduction
This lab is will help us understand the differences among the autosomes (chromosomes
#1-22) and the sex chromosomes (Chromosome #23).
With the help of the human genome project, scientists have mapped the location of many
genes in human chromosomes. The locations of important mapped genes are shown on
your chromosomes.
Objectives
Combine your chromosomes with another member of the class and determine the
genetic make-up of the child that should be produced
Use mapped genes to determine the genotype and phenotype of your offspring
Procedure
1. Find your lab partner by locating the person with the same numbered envelope. The
envelope that you received contains paternal (male) or maternal (female)
chromosomes. If your chromosomes are pink, you are the mother. If your
chromosomes are blue, you are the father.
2. Once you and your partner find each other, spread out the contents of each of your
envelopes. Mix up the chromosomes then try to match them up together by number,
size, banding, gene location, etc. Occasionally, there may be a missing or extra
chromosome. In this instance, you have a genetic disorder.
3. After you finish karyotyping your chromosomes, you should notice that your baby
probably has one type of genetic disease.
4. Use this karyotype to answer the following questions. Then put the chromosomes
back in their respective envelopes. Be sure to inform the teacher of any
chromosomes that are missing.
Results
COUPLE NUMBER
SEX OF CHILD
GENETIC DISEASE
WHICH DISEASE IS HE/SHE A
CARRIER OF?
BLOOD TYPE
HAIR COLOR
EYE COLOR
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Discussion
1. How many chromosomes are found in human sperm?
2. How many chromosomes are found in human ova?
3. How many chromosomes are found in each cell of a newborn child?
4. How many chromosomes are found in your created child from this lab?
5. What form of cell division creates gametes (sperm and egg)?
6. Which form of cell division creates identical diploid cells?
7. What is the relative size of an X-chromosome to a Y-chromosome?
8. What genetic disorder(s) did the sperm carry?
9. Which genetic disorder(s) did the egg carry?
10. What genetic disorder has your baby inherited?
Going Further
After you complete the karyotyping lab you will discover that your baby has inherited a
combination of genes or chromosomes that result in a genetic disease. Your assignment
is to find information on your baby’s genetic disease, including: Symptoms, onset,
frequency, mode of inheritance, chromosome and locus, treatment, and lifespan.
P a g e | 80
Radioactive Decay
Introduction
It was not until the end of the 1800s that scientists found a method for determining the actual age
of rocks and minerals. They found that a given mass of a radioactive element decays, or changes
to other elements, by giving off particles and energy at a constant measurable rate. Scientists also
found that for each different radioactive element the rate of change was fixed and not at all
affected by such things as the pressure or temperature of the surrounding environment. The
decay process is so regular that it can literally be used to determine the passage of time like the
ticking of a clock.
In this activity you will use a mathematical model to study the process of radioactive decay in
order to help understand how it can be used to determine the age of ancient earth materials. For
this activity, it will be helpful to remember that the term half-life refers to the time required for
half of the atoms of a given mass of substance to decay.
Objective
To gain an understanding of what is meant by a half-life.
Materials
cardboard box with lid plastic cup with corn kernels
graph paper
Procedure
1. Count out exactly 100 kernels of corn and place them in the box provided. Note that the
insides of the box have been numbered 1 - 4.
2. Place the lid on the box and give it one hard shake and place it on the lab table.
3. Carefully open the box and remove all the corn kernels that have the small end pointing
toward the side numbered 1. Count them and subtract that number from 100. This will be
the number of kernels remaining in the box. Record this number in the proper place in the
data table. Do not return the kernels you removed from the box.
4. Replace the lid and give the box another shake and once more remove all the kernels
pointing toward side 1. Count them and subtract this number from those remaining from
the previous shake. Record this new figure in the data table.
5. Repeat this process until all of the corn kernels have been removed from the box.
6. Return all 100 pieces of corn to the box, cover it, and repeat the above procedure; except
this time, after each shake, remove all the kernels pointing towards both sides 1 and 2.
Calculate the corn remaining in the box and record your data.
7. Continue this procedure until all the corn has been removed from the box.
8. Finally, return all 100 pieces of corn to the box and repeat the entire procedure a third
time, except after each shake remove all those kernels pointing toward sides 1, 2 and 3.
Continue this process again until all kernels have been removed. Make sure to record
your data in the proper place in the data table.
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Results
Shake # Substance A Substance B Substance C
Corn Remaining Corn Remaining Corn Remaining
Side 1 Test Sides 1,2 Test Sides 1,2,3 Test
0 100 100 100
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
**Using your data, construct a graph with number of corn kernels remaining on the Y-axis and
number of shakes on the X-axis. Your graph should have 3 lines, each representing a different
substance.
P a g e | 82
Discussion
1. Estimate the half-life for each set of data (approx. # of shakes to reduce kernel number by one
half)?
2. Are the half-lives the same or different for each substance? Explain.
3. Radioactive C14 has a half life of 5,770 years, decaying into N14. Assuming living things take
in C14 while alive, you can compare it to how much N14 exists in a sample. If a fossil is found to
consist of 1/8 the amount of C14 it would be expected to have, how old would it be? Show your
work.
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Examining the Fossil Record
Objectives
Analyze characteristics of fossils
Compare placement of fossils and determine relative ages
Develop a model evolutionary tree based on the morphology and age of fossils
Background
Fossils are traces of organisms that lived in the past. When fossils are found, they are
analyzed to determine the age of the fossil. The absolute age of the fossil can be
determined though radiometric dating and determining the layer of rock in which the
fossil was found. Older layers are found deeper within the earth than newer layers.
The age and morphologies (appearances) of fossils can be used to place fossils in
sequences that often show patterns of changes that have occurred over time. This
relationship can be depicted in an evolutionary tree, also known as a phylogenetic tree.
There are two major hypotheses on how evolution takes place: gradualism and
punctuated equilibrium. Gradualism suggests that organisms evolve through a process
of slow and constant change. For instance, an organism that shows a fossil record of
gradually increased size in small steps, or an organism that shows a gradual loss of a
structure. Punctuated equilibrium suggests that species evolve very rapidly and then stay
the same for a large period of time. This rapid change is attributed to a mutation in a few
essential genes. The sudden appearance of new structures could be explained by
punctuated equilibrium.
Speciation
The fossil record cannot accurately determine when one species becomes another species.
However, two hypotheses regarding speciation also exist. Phyletic speciation suggests
that abrupt mutations in a few regulatory genes occur after a species has existed for a
long period of time. This mutation results in the entire species shifting to a new species.
Phyletic speciation would also relate to the Punctuated Equilibrium hypothesis regarding
evolution. Divergent speciation suggests that a gradual accumulation of small genetic
changes results in subpopulation of a species that eventually accumulate so many changes
that the subpopulations become different species. This hypothesis would coincide with
the gradualism model of evolution. Most evolutionary biologists accept that a
combination of the two models has affected the evolution of species over time.
P a g e | 84
Procedure
1. The diagram you are creating requires a large space. To create your workspace, tape
together 6 sheets of standard sized paper. Use a ruler to draw the following chart on your
workspace
Time Period Began (years ago) Fossils
( 2 inches wide) ( 2 inches wide) (7 inches wide)
Wyomingion
995,000 (6 inches tall)
(oldest)
Ohioian 745, 000 (6 inches tall)
Nevadian 545,000 (6 inches tall)
Texian 445,000 (6 inches tall)
Oregonian 395,000 (6 inches tall)
Coloradian 320,000 (6 inches tall)
Montanian 170,000 (6 inches tall)
Californian 80,000 (6 inches tall)
Idahoan (present) 30,000 (6 inches tall)
2. The groups of "fossils" you will work with are fictitious animals. Each fossil on your
sheet is marked with a time period. Cut out each fossil and make sure you include the
time period marked below it.
3. Arrange the fossils by age. On your data chart, place each fossil next to the period from
which the fossil came from. The term "upper" means more recent and should be placed
lower than the low. The term "lower" means an earlier time period, fossils from a "lower"
time period should be place toward the older time periods. In each fossil column, you
may have 3 specimens, one from the main time period, one from the upper, and one from
P a g e | 85
the lower. Not all fossils are represented, illustrating the incompleteness of any fossil
record.
4. While keeping the fossils in the proper age order, arrange
them by morphology (appearance). To help you understand
the morphology of the specimen, view the diagram to the
right. Arrange the fossils using the following steps:
a. Center the oldest fossil at the top of the fossil column
(toward the oldest layer)
b. Throughout the chart, those fossils that appear to be the same (or close to the same)
as the fossils preceding them should be placed in a vertical line
c. During a certain period, the fossils will split into two branches. In other words, one
fossil from that period will show one type of change, and another fossil will show a
different change. When this happens, place the fossils side by side in the appropriate
time period. From this point on you will have two lineages.
5. Once all the fossils have been placed correctly according to time and morphology, tape
or glue the fossils in place.
Discussion
1. Give a brief description of the evolutionary changes that occurred in the organism.
2. During which time period(s) did the fossils differentiate into two branches?
3. Explain how the chart illustrates both punctuated equilibrium and gradualism. Use
specific fossils from the chart to support your answer.
4. Making the assumption that each fossil represents a separate species. Explain how the
chart illustrates divergent and phyletic speciation. Use specific fossils from the chart to
support your answer.
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5. Define the following terms:
morphology –
fossil –
phylogenetic tree –
6. Examine the fossil that was unearthed in a museum, apparently the labels and other
information were lost.
Based on the fossil record, this fossil is likely from what period?
7. There were two different species found during the Upper Montantian period. When
did these species share a common ancestor? How do you know?
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8. What environmental conditions do you suppose led to each of the different lineages?
How is each lineage adapted for their environment?
9. Which of the two major species that arose from the parent species was more
successful? How do you know?
10. For each of the "blanks" on your fossil record, make a sketch of what the animal
would look like. Draw them directly on your fossil record. Also draw in the environment
in the background for where you would have expected the organisms to live.
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Fossils
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Natural Selection: The driving force of evolutionary change
Big Ideas
Favorable traits increase the “fitness” an organism.
An organism’s “fitness” involves:
o The likelihood that it will survive, and
o The amount of offspring that it is likely to produce.
Over time, as more “fit” members of a population survive more and reproduce
more, populations will become more and more “fit” overall (i.e. the “fittest” traits
will become more and more prevalent over time).
Related Ideas
Communities have carrying capacities, meaning that they can only support a
limited amount of organisms.
Competition for resources occurs between individuals of a population, where
more fit individuals are more likely to survive.
Competition for resources occurs between populations of a community, where
more fit populations are likely to survive.
New traits randomly occur. They do not occur on an “as needed” basis.
Changes in the environment can change the fitness of organisms, and therefore
alter the path of evolutionary change.
Materials (per group)
1 penny Handful of Styrofoam
1 paper bag Plastic wrap
1 plastic bag Paper towels
1 straw (cut into 2 halves) Scotch Tape
Handful of cotton balls
Other materials (per class)
Electric fan (large and powerful if possible, elevated about 1-2 meters off the
ground if possible)
10-m tape measure
As much unobstructed space as possible for a “testing area”, preferably with a
hard floor so the seeds can “slide” a little too.
Optional: Feathers, Filter Paper, Rubber Bands, Thread/Needle
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Introduction
As a team of field ecologists, you have been asked to conduct a study of population
change over time. More specifically, you have been asked to accumulate data about how
the newly discovered plant species Plantus pennius adapts to its environment over time.
This is a plant whose seeds look like pennies, and their primary means of seed dispersal
is by wind.
Upon discovering the initial population, you notice that the seeds actually show
enormous variation. They all contain the part that looks like a penny because this is the
actual seed that will germinate into a new plant. They seem to come in a vast variety of
casings, though. This discovery leads you to form a hypothesis that the type of seed a
particular plant produces will be directly related to the likelihood that the plant will
survive and reproduce.
Phase I: Discovering the initial population
Each lab group will represent a different seed (and therefore a different plant) in each of
two generations. The first generation will be the initially discovered population. The
second generation will represent the population after one round of “adaptation” to the
environment. Table 1 represents the traits that we will use, the variations of those traits,
and the abbreviations that we will use for them.
Table 1: Alleles and abbreviations
Trait # Dominant allele Recessive allele
1 Paper bag casing P Plastic bag casing p
2 Seed taped to inside wall of bag. T Seed freely placed in bag t
3 Bag casing is closed L Bag is open-ended l
Bag shape internally supported with Bag shape contains no straw
4
1 straw half per allele
R supports
r
5 Bag contains cotton balls F Bag contains no cotton balls f
6 Bag contains Styrofoam M Bag contains no Styrofoam m
7 “Parachute” attached H No parachute h
8 Plastic wrap parachute B Paper towel parachute b
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Now discover what the traits of your initial individual plant seed will be. Remember,
every organism will have two alleles for every trait, which can be the same or different.
1. Determine the alleles for the first trait (paper bag casing or plastic bag casing) by
rolling the die twice (once for each allele). Document the number of each roll in
Table 3. Repeat for each trait.
2. Determine the alleles your individual will have for each trait. Refer to Table 2
below to determine which numbers rolled represent which alleles. Then document
the genotypes in Table 3.
Table 2: Rules for determining alleles
Trait # Roll Allele Roll allele
1 1, 2, 3 P 4, 5, 6 p
2 1, 2, 3, 4 T 5, 6 t
3 1, 2, 3 L 4, 5, 6 l
4 1, 2, 3, 4 R 5, 6 r
5 1, 2 F 3, 4, 5, 6 f
6 1, 2, 3 M 4, 5, 6 m
7 1, 2 H 3, 4, 5, 6 h
8 1, 2, 3 B 4, 5, 6 b
3. Based on the genotype, determine the phenotype of your individual seed for each
trait, and document it in Table 3. Refer to Table 1 as a reminder of what the
alleles mean.
4. Combine all of the phenotypes you discovered, and build a model of your initial
seed using the materials available to you.
Table 3: Traits of the initial individual
Numbers rolled Genotype
Trait Phenotype
Roll 1 Roll 2 Allele 1 Allele 2
1. Paper or plastic?
2. Taped to inside?
3. Closed or open?
4. Straw supports?
5. Cotton?
6. Styrofoam?
7. Parachute?
8. plastic or paper?
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Phase 2: Determining which individuals are most fit
Now we are going to determine which seeds in the population are the “fittest” ones. We
will simulate seed dispersal by wind by letting our seeds go in front of a fan, and we will
claim that the “fittest” seeds in our population are the ones capable of dispersing the
farthest.
Before we start, let’s form some hypotheses. Document in Table 4 which traits you
believe might contribute to making seeds most “fit” (i.e. document which traits you
believe will be better for the seeds). Place check marks in the appropriate boxes.
Table 4: Fitness hypotheses for each trait
Dominant phenotype Recessive phenotype
Paper bag casing Plastic bag casing
Seed taped to inside wall of bag Seed freely placed in bag
Bag casing is closed Bag is open-ended
Bag shape internally supported with 1
Bag shape contains no straw supports
straw half per allele
Bag contains cotton Bag contains no cotton
Bag contains Styrofoam Bag contains no Styrofoam
“Parachute” attached No parachute
Plastic wrap parachute Paper towel parachute
Now we will run our first simulation of wind seed dispersal.
1. Lay out the measuring tape in front of the fan so that it measures the distance
away.
2. Release your seed in front of the fan (which should be elevated and set to its
highest power).
3. Measure the distance that your penny travels to the nearest millimeter.
Remember, the actual penny is the important part, so your final measurement
should represent the distance that the penny travels. If time permits, you may take
three trials, and average them. Record your group’s data in Table 5.
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Table 5: My seed’s dispersal distance data
Trial 1 distance (m) Trial 2 distance (m) Trial 3 distance Average distance (m)
(m)
Now record your own seed’s average distance, as well as the average distances for all
other groups in Table 6. When all groups have completed their simulations, rank their
fitnesses, with #1 being the best. Finally, average all of the averages in the table, and
record this as the average population dispersal distance below Table 6.
Table 6: First generation dispersal distances:
Average dispersal
Group members Fitness rank
distance (meters)
My group
Average population dispersal distance:
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Phase 3: Passing on the traits
Now that we have data that ranks the seeds in order of fitness, here are the rules about
which seeds survived, which seeds flourished, and which seeds met a very sad fate.
Top 3 seeds:
Your plants are of excellent fitness. Twice as many of your plants survive as the
“average” plant. The bottom 3 groups (whose plants did not survive) will assume
responsibility for your duplicates for reproduction purposes. Your original plant will
reproduce, so document your initial genotypes into the first two columns of Table 7 (“My
plant”). See Table 3 as a reminder of your initial genotypes.
Bottom 3 seeds:
Your seeds are not very fit at all. None of your plants survived. You have been replaced
by one of the top 3, and you will assume responsibility for one of the top 3 seeds for
reproduction purposes.
Last place Assume responsibility for the extra “first place” seed,
which is now your plant. Document the genotypes of your
new plant into the first two columns of Table 7 (“My
plant”).
2nd to last place Assume responsibility for the extra “second place” seed,
which is now your plant. Document the genotypes of your
new plant into the first two columns of Table 7 (“My
plant”).
3rd to last place Assume responsibility for the extra “third place” seed,
which is now your plant. Document the genotypes of your
new plant into the first two columns of Table 7 (“My
plant”).
All other seeds:
Your seeds are of average fitness, and your numbers have remained stable. Your original
plant will reproduce, so document your initial genotypes into the first two columns of
Table 7 (“My plant”). See table 3 as a reminder of your initial genotypes.
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Now that we all have plants that will reproduce for the next generation, all of our plants
must be crossed with another.
1. Your group should pick another lab group at random, and cross your plants.
2. Document the genotypes of the plant with which you are crossing yours in
columns 3 and 4 of Table 7 (“Crossed with”).
3. Your pair of plants will produce two unique offspring, so separate yourselves and
complete the following reproduction rules on your own in Table 7.
a. Allele 1 of your offspring will come from your plant (“My plant” column).
It will either be allele 1 or allele 2 from your plant (“My plant”). Roll the
die. If it is odd, allele 1 of your offspring will be allele 1 from the parent.
If it is even, allele 1 of the offspring will be allele 2 from the parent.
b. Allele 2 of your offspring will come from the other parent (the “Crossed
with” column). Repeat step (a) to determine which allele from the other
parent will become allele 2 of the offspring.
c. Repeat steps (a) and (b) for the remaining traits.
d. Document the phenotypes of the offspring.
4. Now, build a model of your offspring. Each group will do this since there are 2
unique offspring per pair of mating plants.
Table 7: Reproduction chart
My plant Crossed with Offspring
Trait #
Allele 1 Allele 2 Allele 1 Allele 2 Allele 1 Allele 2 Phenotype
1
2
3
4
5
6
7
8
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Phase 4: The next generation
Now, we are going to test the seeds of the next generation of Plantus pennius plants.
Repeat all testing procedures from Phase 2 of this investigation, and complete the charts
below.
Table 8: My offspring’s dispersal distance data
Trial 1 distance (m) Trial 2 distance (m) Trial 3 distance Average distance (m)
(m)
Table 9: Next generation dispersal distances:
Average dispersal
Group members Fitness rank
distance (meters)
My group
Average population dispersal distance:
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Phase 5: Tallying the data
Now, we are going to summarize the data that compares the fitness of Plantus pennius
plants to the possible phenotypes and alleles.
Mingle as a class, tally the total number of alleles and phenotypes in the first and second
generations, and document them in Table 10. Everyone should refer to Table 3 for
generation 1 data and Table 7 for generation 2 data.
Table 10: Dominant allele and phenotype tallies for the first and second generation population.
Alleles Phenotypes
Traits Generation Generation Generation Generation
1 2 1 2
1 Paper bag casing P
2 Seed taped to inside T
3 Bag casing is closed L
4 Internal straw supports R
5 Bag contains cotton F
6 Bag contains Styrofoam M
7 “Parachute” attached H
8 Plastic wrap parachute B
Table 11: Recessive allele and phenotype tallies for the first and second generation population.
Alleles Phenotypes
Traits Generation Generation Generation Generation
1 2 1 2
1 Plastic bag casing p
2 Seed freely placed in bag t
3 Bag is open-ended l
4 No internal supports r
5 No cotton f
6 No Styrofoam m
7 No parachute h
8 Paper towel parachute b
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Phase 6: Analysis
1. List two reasons why seeds capable of dispersing long distances could be
considered more “fit” than seeds incapable of dispersing long distances.
2. Think of two other types of traits a plant seed could have that would qualify it as
more fit than a plain naked seed that simply drops to the ground. Explain.
3. Refer back to table 1 that summarizes the dominant and recessive traits. Apply
your knowledge about what makes a trait “dominant” and what makes a trait
“recessive.” Choose any two of these traits, and explain why (on a molecular
level) these traits might be dominant.
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4. Did the population become more fit? How does your data support your
conclusion? What do you believe is the ultimate fate of the Plantus pennius
population in this community?
5. Assuming this population of Plantus pennius survives far into the future, what
would you expect the future of this population to look like (as far as the seeds are
concerned)? Hint: Which would you say would be the “top 5 fittest” alleles?
6. Look at Tables 10 and 11. Why are the two boxes crossed out in each chart as
though they do not apply? What type of inheritance pattern does this represent?
Hint: refer to Table 1.
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7. We focused on dispersal distance alone when analyzing the fitness level of these
Plantus pennius plants. If over time this environment became almost totally
absent of wind, though, this would change things drastically! Name two large-
scale types of environmental change that could change the evolutionary direction
of this population. Also describe what the fittest seeds might look like in these
two situations.
8. Look back at Table 2. Notice that dominant alleles were not always associated
with more possibilities of rolling the die. How do you explain this, and how does
it relate to real life?
9. Is this lab more consistent with Lamarck’s or Darwin’s ideas about how life
changes (evolves) over time?
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Animal Classification and Diversity
Using the Animal Diversity Web:
http://animaldiversity.ummz.umich.edu/site/index.html
Choose a class of animals (ex. Mammalia, Reptilia, Insecta) to research.
Within this class, you must classify 10 distinct species.
Use the taxonomy of each of these ten different species to develop a phylogenetic
tree of the species.
o Explain how the taxonomy of the organism helped you to develop a
branching pattern between the species.
Once you have completed the tree, choose three of the species.
Use a search engine on the internet to research the similarities and differences
between the three organisms. Key points can include physical characteristics,
behavior, habitat, and role in the food web.
o Explain which two of the three organisms are most closely related and
what makes the third different from the other two.
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Squid Dissection
Living organisms have two main goals:
To strive for their own survival as individuals. They do this by:
o Responding to their environment.
o Obtaining, processing, and disposing energy.
o Maintaining a stable internal environment a (process called
homeostasis).
To strive for the survival of the species. They do this by
o Adapting to their environment over time (a process called evolution).
o Reproducing.
As you dissect the squid, freely inspect the external and internal anatomy. Your goal is to
identify internal and external features of the squid as falling under one of the above
categories. There is substantial overlap between the categories above! For example, teeth
can fall under getting energy if it is used for digesting food, and for responding to the
environment in cases where they are used purely for self defense.
Feel free to use any resources available to assist you in completing the requirements:
Requirements:
Physically locate 12 anatomical features of your squid.
o At least 8 of your features must be internal.
o At least 2 of your features must be external.
Describe how they fit under one of the 5 categories (response, energy,
homeostasis, evolution, or reproduction):
o You must have at least 1 feature describing each category.
Note your ideas in the following chart.
When the above requirements are complete, notify your teacher.
Each lab partner will verbally explain your group’s conclusions.
o Each partner will be responsible for explaining an appropriate number
of conclusions based on the size of the group.
o With a dissecting probe, physically point out the features as you
explain them to your teacher. (As you do this, I will initial your
charts.)
Obtain initials from your teacher and submit your lab handout.
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6.
5.
4.
3.
2.
1.
Anatomical
feature
Internal
(at least 8)
External
(at least 2)
Response
(at least 1)
Energy
(at least 1)
Homeostasis
(at least 1)
Adaptation
(at least 1)
Reproduction
(at least 1)
Description of how the feature relates to the category.
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12.
11.
10.
9.
8.
7.
Anatomical feature
Internal
(at least 8)
External
(at least 2)
Response
(at least 1)
Energy
(at least 1)
Homeostasis
(at least 1)
Adaptation
(at least 1)
Reproduction
(at least 1)
Description of how the feature relates to the category.
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Frog Dissection
Living organisms have two main goals:
To strive for their own survival as individuals. They do this by:
o Responding to their environment.
o Obtaining, processing, and disposing energy.
o Maintaining a stable internal environment a (process called
homeostasis).
To strive for the survival of the species. They do this by
o Adapting to their environment over time (a process called evolution).
o Reproducing.
As you dissect the frog, freely inspect the external and internal anatomy. Your goal is to
identify internal and external features of the frog as falling under one of the above
categories. Keep in mind that there is substantial overlap between the categories above.
For example, teeth can fall under getting energy if it is used for digesting food, and for
responding to the environment in cases where they are used purely for self defense.
Feel free to use any resources available to assist you in completing the requirements:
Requirements:
Physically locate 12 anatomical features of your frog.
o At least 8 of your features must be internal.
o At least 2 of your features must be external.
Describe how they fit under one of the 5 categories (response, energy,
homeostasis, evolution, or reproduction):
o You must have at least 1 feature describing each category.
Note your ideas in the following chart.
When the above requirements are complete, notify your teacher.
Each lab partner will verbally explain your group’s conclusions.
o Each partner will be responsible for explaining an appropriate number
of conclusions based on the size of the group.
o With a dissecting probe, physically point out the features as you
explain them to your teacher. (As you do this, I will initial your
charts.)
Obtain initials from your teacher and submit your lab handout.
P a g e | 106
6.
5.
4.
3.
2.
1.
Anatomical
feature
Internal
(at least 8)
External
(at least 2)
Response
(at least 1)
Energy
(at least 1)
Homeostasis
(at least 1)
Adaptation
(at least 1)
Reproduction
(at least 1)
Description of how the feature relates to the category.
P a g e | 107
12.
11.
10.
9.
8.
7.
Anatomical feature
Internal
(at least 8)
External
(at least 2)
Response
(at least 1)
Energy
(at least 1)
Homeostasis
(at least 1)
Adaptation
(at least 1)
Reproduction
(at least 1)
Description of how the feature relates to the category.
