AP BIOLOGY

Detailed explanation-1: -Homozygous is a word that refers to a particular gene that has identical alleles on both homologous chromosomes. It is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.

Detailed explanation-2: -Returning to our question, a homozygous dominant genotype would have two uppercase P alleles because homozygous means that they would match, whereas a heterozygous dominant genotype would have an uppercase P and a lowercase p because heterozygous means that the alleles don’t match.

Detailed explanation-3: -With eye color, for instance, “B” stands for a brown allele and “b” stands for a blue allele. An organism with two dominant alleles for a trait is said to have a homozygous dominant genotype. Using the eye color example, this genotype is written BB.

Detailed explanation-4: -An organism can be either homozygous dominant (TT) or homozygous recessive (tt). If an organism has two different alleles (Tt) for a certain gene, it is known as heterozygous (hetero means different).