Tay-Sachs is inherited as an autosomal recessive allele. Homozygous individuals die within the first few years of life. However, there is some evidence that heterozygous individuals are more resistant to tuberculosis. Which of the following statements about Tay-Sachs is true?
A)The allele for Tay-Sachs is selected against.
B)This situation is an example of heterozygote advantage if tuberculosis is present in a population.
C)This situation is an example of disruptive selection.
D)Heterozygotes will be more fit than either homozygote regardless of environmental conditions.

Question

Quizplus · Accepted Answer

This situation is an example of heterozygote advantage due to the increased resistance to tuberculosis. This means that the heterozygous individuals have a higher fitness than either homozygote in the presence of tuberculosis. The allele for Tay-Sachs is still recessive and selected against in homozygous individuals, but it provides a benefit to heterozygotes in certain environments.

Tay-Sachs Is Inherited as an Autosomal Recessive Allele