Question

Around a pond, there is a small population of turtles. Some of them have solid dark brown shells and some of them have yellow and brown shells with yellow spots. Spotted shells are dominant over solid shells. Six of the turtles are homozygous for the spotted shells, four are heterozygous and two are homozygous for the solid shells.

1. How many total alleles are there in this particular gene pool?

2. How many dominant alleles are there? Recessive?

3. Calculate the allele frequency for the dominant and the recessive allele.


4. If over time, due to a change in the environment, the solid dark brown shells became the advantageous color, what would likely happen to the frequencies of the gene pool?

5. If the allele frequency of a particular trait is 100 percent, describe the genetic variation for that trait in the population.

Answer 1

1. 2 alleles, solid brown and spotted

2. 1 dominant, spotted, and one recessive, solid

3. Dominant: 16/24 Recessive: 8/24. Spotted- R, solid, r. There are 6 RR, 4 Rr and 2 rr.

4. It would slowly become more common and common. When a spotted and a solid pairs, its still most likely that the offspring will be spotted, however as most spotted die the number of spotted getting offsprings decrease.

5. No genetic variation, everyone in the population has that trait