AP BIOLOGY

Detailed explanation-1: -Sally’s genotype is “dd", so she is also considered homozygous. Susan’s genotype is “Dd", so she is considered HETEROZYGOUS (has two different alleles for a specific gene).

Detailed explanation-2: -Individuals who are homozygous dominant (DD) or heterozygous (Dd) are Rh+. Those who are homozygous recessive (dd) are Rh-(i.e., they do not have the key Rh antigens). Clinically, the Rh factor, like ABO factors, can lead to serious medical complications.

Detailed explanation-3: -"AA” is homozygous because both the alleles are the same. “Homo” typically means “the same.” A heterozygous genotype would be something like “Aa” or “Bb” where the alleles in each genotype are different.

Detailed explanation-4: -The DD, Dd, dd, and DI are all genotypes that are responsible for the production of a physical characteristic. DD is a homozygous dominant combination, Dd is a heterozygous dominant combination, dd is a homozygous recessive combination, and DI is an incorrect combination as it contains different alleles.

Detailed explanation-5: -Background: The DD genotype gene is a linkage marker for an etiologic mutation at or near the angiotensin-converting enzyme gene and has been associated with increased risk for the development of coronary artery disease, left ventricular hypertrophy and left ventricular dilation after myocardial infarction.