Question

if a genetic disorder is caused by a dominant allele, individuals with which of the following genotypes would be affected by the disorder?
○ aa and aa
○ aa and aa
○ aa and aa
○ aa, aa, and aa

Explanation:

For a dominant genetic disorder, the dominant allele (A) expresses the disorder. Genotype AA has two dominant alleles, and Aa has one dominant allele—both will show the disorder. aa has two recessive alleles, so it won't. So AA and Aa are affected.

Answer:

B. AA and Aa (assuming the second option is labeled as B; if the original options' labels aren't given, but the second option text is "AA and Aa", then the answer is the option with text "AA and Aa")