Question

A pedigree chart is shown below for a disease that is autosomal dominant. The genetic make-up of the first generation is:

• A. AA, Aa
• B. Aa, aa
• C. Aa, AA
• D. Aa, Aa

Hint:

In autosomal dominant inheritance, unaffected children from affected parents indicate both parents are heterozygous (Aa).

Answer 1

The Correct Option is D

The disease is autosomal dominant, so affected individuals must have at least one dominant allele (A). The first generation (parents) have both affected and unaffected children, which means they must both be heterozygous (Aa) to produce both affected (Aa or AA) and unaffected (aa) offspring.