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On a certain plant, you want to study the inheritance of two genes, P and R

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On a certain plant, you want to study the inheritance of two genes, P and R.

1. Plot the gametes of a PPrr × PpRr cross onto a Punnett square below. Note: you may not need to draw an entire 4x4 square.

 

2. If P (purple petals) is dominant to white petals, and R (round seeds) is dominant to wrinkled, what is the probability of producing a purple - petaled, round-seeded plant?

3. Which cellular process—that we covered earlier this semester—illustrates the principle of segregation?

Below is a pedigree of red-green colorblindness.

4. The genotype of individual I-1 is what?

5. Circle all the statements that we can say with certainty regarding the pedigree:

a. Individual II-5 inherited the allele causing colorblindness from his father.

b. Individual III-8 is a carrier.

c. Individual II-2 is a carrier.

d. Individual II-5 passed on the recessive allele to individual III-8.

6. If individuals III-8 and III-9 have another child, what is the probability that they will have a carrier daughter?

7. If individuals III-8 and III-9 have another child, what is the probability that their next son will not be colorblind?

8. If individuals III-8 and III-9 have another child, what is the probability that will have a female homozygous dominant daughter?

The ewoks on the forest moon of Endor come in many fur colors. Ewoks with black fur are dominant (BB), and ewoks with tan fur are recessive (bb). Before the battle of Endor, you survey the ewoks and discover 160 out of 200 have tan fur. Assume the population is in Hardy-Weinberg equilibrium.

9. What is the frequency of the homozygous dominant allele?

10. What is the frequency of the homozygous dominant genotype?

11. How many ewoks would you expect to have the heterozygous genotype?

Big-whisker syndrome is a homozygous recessive condition in mountain mice. Consider a hypothetical population of 3000 individuals where Hardy-Weinberg equilibrium is met. Suppose the frequency of the dominant allele is 0.7.

12. How many individuals would you expect to have the homozygous dominant genotype?

13. What proportion of the population would you expect to be heterozygous?

14. How many individuals do you expect to be heterozygous?

It so happens that the big-whisker data from above was from the year 2000. You are now provided with updated data current as of 2020: the homozygous dominant genotype frequency is 0.63, and the homozygous recessive allele frequency is 0.11.

15. Is the population in Hardy-Weinberg equilibrium? Explain why or why not. Refer to the dominant and recessive allele frequencies in your response.

16. What does this imply about the population? Has it changed at all in the last two decades?

17. Circle the statements that are true regarding this scenario:

a. If the population is evolving, it could be due to genetic drift or natural selection.

b. If there is no genetic drift and no natural selection, the population is not evolving.

c. Gene flow could serve as a counterbalance to genetic drift, preventing evolution.

d. If this population is isolated, gene flow would be the easiest Hardy-Weinberg assumption to control regarding this population.

e. A bottleneck effect would have no impact on the evolution of this population.

For the next four statements, indicate whether the statement is true of false, and then briefly explain your reasoning.

18. This diagram suggests that there is gene flow between the two populations at this particular section of the river.

19. This diagram shows genetic drift in one or both populations.

20. This diagram depicts the origin of a new allele via mutation.

21. This diagram shows that evolution is occurring.

22. At Time 2, what is the frequency of allele g in the population on the right side of the river?