Mutations in the GDF9 gene in sheep have been linked to changes in female fecundity. The following are the relative fitnesses of different genotypes in the population. Which statement below is correct?
Genotype Relative fitness
+/ - &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp1
+/ + &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp0.7
-/ - &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp0.1
A) This is an example of heterozygote advantage; genetic variation will be maintained over time.
B) This is an example of negative frequency-dependent selection; genetic variation will be maintained over time.
C) This is an example of heterozygote advantage; genetic variation will be lost over time.
D) This is an example of negative frequency-dependent selection; genetic variation will be lost over time.

Question

Mutations in the GDF9 gene in sheep have been linked to changes in female fecundity. The following are the relative fitnesses of different genotypes in the population. Which statement below is correct? 
Genotype Relative fitness
+/ -  &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp1
+/ + &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp0.7
-/ - &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp0.1
A) This is an example of heterozygote advantage; genetic variation will be maintained over time.
B) This is an example of negative frequency-dependent selection; genetic variation will be maintained over time.
C) This is an example of heterozygote advantage; genetic variation will be lost over time.
D) This is an example of negative frequency-dependent selection; genetic variation will be lost over time.

Quizplus · Accepted Answer

This is an example of heterozygote advantage because the heterozygous genotype (+/-) has the highest relative fitness (1), which means it will be favored by natural selection, thereby maintaining genetic variation in the population over time.

Mutations in the GDF9 Gene in Sheep Have Been Linked