Question

A large population of fish live in a lake. The color of their scales is determined by two different alleles of the S gene, S1 and S2. Homozygous S1 fish have yellow scales, S2 homozygotes have blue scales, and heterozygotes are green. Scientists catch 100 fish at random and record their colors. Among those 100 fish are 30 yellow, 50 blue, and 20 green ones.

After the original sample is analyzed, an asteroid landed in the lake and killed all the fish that happened to be in one location in the lake greatly reducing the overall population size. When 100 fish were sampled again, 15 were yellow, 75 were blue, and 10 were green.

1) What is the frequency of the S1 allele in the population before the asteroid hit?

-0.40

-0.15

-0.50

-0.60

-0.80

2) Was the fish population in Hardy-Weinberg equilibrium before the asteroid hit?

-Yes, because there were 3 colors of fish.

-Yes, because the frequency of yellow fish observed equaled the frequency of yellow fish expected.

-No, because the frequency of yellow fish observed did not equal the frequency of yellow fish expected.

-No, because the frequency of yellow fish observed did not equal the frequency of the S¹allele.

3) Hardy-Weinberg conditions were established in the lake after the asteroid hit. The fish population mated and produced the next generation. Scientists sampled 100 fish that were all offspring of the post-asteroid population. How many yellow fish will be among the 100 offspring sampled?

-4

-8

-15

-30

-32

Answer 1

Answer is attached