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Adaptation

Investigation 2 – Lab

 

 

 

 

 

 

 

MINDSET

This Investigation is designed to:

  • demonstrate to you how a trait can become advantageous if an environmental pressure results in greater survival of those individuals possessing the trait, and
  • allow you to investigate what occurs to the survival of the individuals of a population when the alleles which encode that trait are inherited.

BE PREPARED

Student Preparation for the Investigation includes gathering the following materials. T

Note: The materials are listed in your SDR. They are also listed below for your reference.

  • (1) clear plastic container
  • (24) dark-colored gram cubes of the same color
  • (24) light-colored gram cubes of the same color
  • (15) pinto beans
  • (4) sunflower seeds
  • (1) metric ruler
  • (4) 50 ml beakers
  • (1) stopwatch
  • (1) pair of forceps
  • (1) calculator

Have one student from each lab group to collect the materials listed in their SDRs.

INVESTIGATE

  • Reflect on the PreLab video as you move through the procedural steps.
  • During the Experiment, every procedural step is important. If one step is skipped, data can become invalid. To help you keep on track, read each step thoroughly, complete the step, then check it off (Read it – Do it – Check it off).
  • Complete all of the procedural steps in your SDR.

Note: The procedural steps are listed below for your reference.

Trial 1:

  1. In this Trial, you will investigate the effect of bone density on the ability of the penguins to catch fish.
  2. Imagine: In the model world, there are 24 penguins. There are two types of penguins. 18 penguins have less dense bones. These penguins can not dive into the deep water so they only eat food that floats on the surface. Six penguins have more dense bones and can dive deep to eat food or can eat food on the surface of the water. The penguins have existed happily for many years, but a change has just started to occur in the environment. The temperature is getting much colder. No food is available on the land and the food floating on the surface of the water is becoming scarce. There is still plenty of food in the deep water.

Adapt Inv. 2 Lab Predition Trial 1

  1. Make a prediction. Will both types of penguins be able to survive in this new environment? Will there be a change in the ratio of penguins with more dense bones to penguins with less dense bones?
  1. Create the penguins that exist in the model world. Use the key in Table A as a guide.

A. Remove the Genotype and Phenotype Page at the end of Investigation 2 and place it on the table. This page will be used to help keep track of the different types of penguins.

B. The penguins will be represented by gram cubes as in Investigation 1.

C. Connect two dark-colored gram cubes to make a penguin with two dominant alleles. This penguin has less dense bones. Make a total of 6 penguins with two dominant alleles. Place the penguins under the correct genotype heading on the Genotype and Phenotype Page.

D. Connect two light-colored gram cubes to make a penguin with two recessive alleles. This penguin has more dense bones. Make 6 penguins like this. Place the penguins under the correct genotype heading on the Genotype and Phenotype Page.

E. Connect a dark-colored gram cube with a light-colored gram cube to make a penguin with one dominant allele and one recessive allele. This penguin has less dense bones. Make 12 penguins like this. Place the penguins under the correct genotype heading on the Genotype and Phenotype Page.

F. There should be a total of 24 penguins. Each penguin should be represented by two gram cubes connected together.

  1. Gather information that will be used to calculate the frequency of alleles in the penguin population.

A. Record: Count the total number of gram cubes that were used to make the penguins. This represents the total number of alleles. Write this number in Table B. If the total number of alleles does not equal 48, please return to step 4.

B. Record: Count the total number of dominant alleles (less dense bones) in the penguin population by counting the number of dark-colored gram cubes. Write this number in Table B.

C. Record: Count the total number of recessive alleles (more dense bones) in the penguin population by counting the number of light-colored gram cubes. Write this number in Table B.

 

6. Calculate: Find the frequency of the dominant allele (less dense bones). Record the number in Table C. Use a calculator and record the answer in Table C. If the answer does not equal 0.50, calculate the answer again.

A. Use the formula:                                                                                                             

B. Use a calculator and record the answer in Table C. If the answer does not equal 0.50, calculate the answer again.

 

7. Calculate: Find the frequency of the recessive allele (more dense bones). Record the number in Table C.

A. Use the formula:

B. Use a calculator and record the answer in Table C. If the answer does not equal 0.50, calculate the answer again.

 

8. Separate the 24 penguins into two groups.

A. Group A has 6 penguins and has more dense bones (homozygous recessive). Place these penguins under the correct phenotype on the Genotype and Phenotype Page.

B. Group B has 18 penguins and has less dense bones (homozygous dominant and heterozygous dominant). Place these penguins under the correct phenotype on the Genotype and Phenotype Page.

 

  1. What is the frequency of the dominant and recessive allele in this population of 24 penguins? 

 

10. Imagine: The penguins are now going to dive for fish. The 6 penguins with more dense bones can catch fish deep in the water or on the surface. The 18 penguins with less dense bones can only catch fish on the surface of the water. You will fish with a pair of forceps. One sunflower seed or one pinto bean will allow a penguin to survive.

11. Fill the clear plastic container with water until water is 3-4 cm from the top of the container.

12. Place 15 pinto beans in the container. These represent the fish that live deep in the ocean.

13. Place 4 sunflower seeds in the container. These represent the fish that live on the surface of the ocean.

14. Go fishing for the penguins with more dense bones.

A. Make sure that 6 penguins with more dense bones are in the “More Dense Bones” box of the Genotype and Phenotype Page.

B. One student should use the stopwatch to keep time.

C. A second student will take the forceps and prepare to go fishing.

D. When the student keeping time says “go”, the person with the forceps will have 25 seconds to catch as many pinto beans and sunflower seeds as possible by picking them up with the forceps.

E. Record: Count the number of fish caught in 25 seconds.

 

15. Calculate how many of the penguins with more dense bones survived.

A. It takes one piece of food to feed each penguin.

B. There were 6 penguins at the beginning of the expedition.

C. If 6 or more “fish” were caught, all the penguins with dense bones survived.

D. If less than 6 “fish” were caught then the number of penguins that survived equals the number of fish caught.

E. If not all the penguins survived, randomly remove the number of penguins that did not survive and place them in the “Dead Penguin” section of the Genotype and Phenotype Page.

F. Record the number of penguins with dense bones that survived in Table D. Place the surviving penguins back in the correct genotype box of the Genotype and Phenotype Page.

 

16. Place the pinto beans and sunflower that were caught back into the tank.

17. Now fish for the penguins with less dense bones.

A. Make sure that 18 penguins with less dense bones are in the “Less Dense Bones” box of the Genotype and Phenotype Page.

B. The penguins with less dense bones can only eat the food on the surface of the water.

C. One student should keep time using the stopwatch. One student should use forceps.

D. When the student keeping time says “go” the student with the forceps will have 25 seconds to catch as many sunflower seeds (but not pinto beans) as possible.

E. Record: Count the number of fish caught in 25 seconds.

 

18. Calculate how many penguins survived.

A. It takes one piece of food to feed a penguin, so the number of penguins that survived is equal to the number of sunflower seeds caught.

B. There were 18 penguins at the beginning of the expedition.

C. Have one student hold all 18 pairs of gram cubes in their hands.

D. Another student will close their eyes and turn to the person who is holding the 18 pairs of gram cubes.

E. The student with their eyes closed will pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if four penguins survived, the student will pick up 4 pairs of gram cubes.

F. Place any penguins that starved in the “Dead Penguin” portion of the Genotype and Phenotype Page.

G. The student will then separate the surviving gram cubes into the correct genotype. Place the surviving penguins in the appropriate genotype box in the Genotype and Phenotype Page.

H. Record the total number of each surviving penguin in Table D.

19. For the surviving penguins, find the frequency of each allele.

A. Count the total number of gram cubes and record in Table E.

B. Count the total number of dark-colored gram cubes (dominant allele) and record in Table E.

C. Count the total number of light-colored gram cubes (recessive allele) and record in Table E.

D. Calculate the frequency of the dominant allele and record the number in Table E. Use a calculator to solve the following formula:

E. Record: Find the frequency of the recessive allele & record the number in Table E. Use a calculator to solve the following formula:

 

20. How many penguins of each different phenotype survived? 

21. Which allele is more common now? 

22. Why did many penguins not survive? 

23. Why did the frequency of the recessive allele increase? 

Adapt Inv. 2 Lab Trial 1 Conclusion Box

 

Trial 2:

1. In this Trial, you will investigate how the surviving penguins pass on their trait for bone density to their offspring.

2. The surviving penguins will randomly mate. Use the blank Punnett square in Table F as a guide.

A. Place the gram cubes representing all of theAdapt Inv. 2 Lab Trial 2 A alleles of all the surviving penguins in a pile.

B. One student should close their eyes and randomly pick two pairs of gram cubes. This will represent a pair of penguins.

C. Place this pair aside.Adapt Inv. 2 Lab Trial 2 B

D. The student should again randomly pick two pairs and put them aside into a separate pile.

E. The student will continue picking pairs until there are no more cubes left. If there is only one penguin left, place this one aside by itself.

3. Each penguin pair will produce one offspring. Use the following procedure for each pair of parent penguins.

A. Take one of the parents, separate the cubes and place the alleles in the boxes to the left of Table F.

B. Take the second parent, separate the cubes and place the alleles on the boxes above Table F.

C. Find all four possible combinations of alleles using Table F. Hint: Often, many of the four combinations will be the same.

D. Make these combinations by connecting gram cubes (there should be extra gram cubes provided). These are the genotypes of the babies that could occur.

E. One student should place the four possibilities in their hands.

F. Another student should close their eyes and randomly choose one of the four combinations. The one chosen will be the new penguin baby.

G. Set the baby penguin aside.

H. Reconnect the two-parent gram cubes and place these aside with the baby.

 4. Repeat the procedure for each pair of penguin parents.

5. Record: Now count all the surviving penguins from the matings.

A. Place all the surviving penguins and their offspring together.

B. Count the number of penguins with two dominant alleles and record in Table G.

C. Count the number of penguins with one dominant and one recessive allele and record in Table G.

D. Count the number of penguins with two recessive alleles and record in Table G.

6. How many penguins of each different phenotype are there? 

7. Record: For the surviving penguins, find the frequency of each allele.

A. Count the total number of gram cubes and record in Table H below.

B. Count the total number of dark-colored gram cubes (dominant allele, less dense bones) and record in Table H.

C. Count the total number of light-colored gram cubes (recessive allele, more dense bones) and record in Table H.

D. Record: Find the frequency of the dominant allele and record the number in Table H. Use a calculator to solve the following formula:

E. Record: Find the frequency of the recessive allele and record the number in Table H. Use a calculator to solve the following formula:

 

8. Which allele is more common now? 

Note: There is an Optional Extension below. Students should complete this portion of the lab as time allows.

CLEAN UP

If you do not continue on to the Optional Extension below, be sure to clean up your bench before leaving the lab.

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OPTIONAL EXTENSION

1. Separate the gram cubes representing the penguins into two piles. One pile is for penguins with dense bones and the second pile is for penguins with less dense bones (homozygous dominant and heterozygous dominant).

2. Repeat the fishing expedition for the penguins with more dense bones.

A. Place the sunflower seeds and pinto beans back in the container. There should be four sunflower seeds on top and 15 pinto beans on the bottom.

B. When the student keeping time says “go”, the student with the forceps will have 25 seconds to catch as many pinto beans and sunflower seeds as possible.

3. Record: How many fish were caught in 25 seconds? ________

4. Record: Determine how many penguins survived.

A. It takes one sunflower or pinto bean to feed each penguin, so the number of penguins that survived is equal to the number of sunflower seeds and pinto beans that were caught.

B. Have one person hold all the pairs of light-colored gram cubes in their hands.

C. Another student will close their eyes and turn to the person who is holding the gram cubes.

D. The student with their eyes closed should pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if four penguins survived, the student should pick up 4 pairs of gram cubes.

E. Set the surviving ones aside.

F. Remove any penguins that starved.

G. Record: Record how many penguins survived in Table I.

5. Repeat the fishing expedition for all the penguins with less dense bones.

A. Place the sunflower seeds back into the container. Remember these penguins can only eat the sunflower seeds because they can not dive deep enough to obtain pinto beans.

B. When the student keeping time says “go”, the student with the forceps will have 25 seconds to catch as many sunflower seeds as possible.

C. Record: How many pieces of food were caught? ____________

6. Record: Count the number of fish caught in 25 seconds __________.

7. Record: Determine how many penguins survived.

A. It takes one sunflower seed to feed each penguin, so the number of penguins that survived is equal to the number of sunflower seeds caught.

B. Have one person hold all the pairs of less dense gram cubes (homozygous dominant and heterozygous dominant) in their hands.

C. Another student should close their eyes and turn to the person who is holding the gram cubes.

D. The student with their eyes closed will pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if four penguins survived, the student will pick up 4 pairs of gram cubes.

E. Remove any penguins that starved.

F. The student will then separate the surviving gram cubes into two piles. One pile will be for the surviving penguins with two dominant alleles and the other pile will be for the surviving penguins with one dominant allele and one recessive allele.

G. Record the total number of each in Table I.

 

 

8. Record: For the surviving penguins, find the frequency of each allele.

A. Count the total number of gram cubes and record them in the chart below.

B. Count the total number of dominant alleles (dark-colored gram cube) and record them in Table J.

C. Count the total number of recessive alleles (light-colored gram cubes) and record them in Table J.

D. To find the frequency of the dominant allele use a calculator to solve the following formula: frequency = (number of dark-colored gram cubes) / (total number of gram cubes).

E. Record in Table J.

F. Calculate the frequency of the dominant alleles.

G. Calculate the frequency of the recessive alleles.

H. Record the frequencies of both alleles in Table J.

Note: The Analysis Questions for the Optional Extension are located on the PostLab page for Investigation 2.

 

CLEAN UP

Be sure to clean up your bench before leaving the lab.