AP BIOLOGY

Detailed explanation-1: -Diploid organisms that are homozygous for a gene have two identical alleles, one on each of their homologous chromosomes. The genotype is often written as YY or yy, for which each letter represents one of the two alleles in the genotype. The dominant allele is capitalized and the recessive allele is lower case.

Detailed explanation-2: -The presence of two identical alleles at a particular gene locus. A homozygous genotype may include two normal alleles or two alleles that have the same variant.

Detailed explanation-3: -homozygous [Operative Neurosurgery] 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-4: -If an organism is heterozygous, the capital letter always comes first. For example: Tt NOT tT.

Detailed explanation-5: -An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype. In our example, this genotype is written Bb. Finally, the genotype of an organism with two recessive alleles is called homozygous recessive.