AP BIOLOGY

Detailed explanation-1: -A dominant trait will always be expressed in the offspring if the dominant allele is present, even if there is only one copy of it (heterozygous or dominant homozygous, Aa or AA).

Detailed explanation-2: -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. 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.

Detailed explanation-3: -bb is called homozygous recessive. Both genes are the same and recessive. The recessive trait is expressed.

Detailed explanation-4: -An individual that contains two copies of the same allele for a specific gene is homozygous. An individual that contains two different alleles of a gene is heterozygous. A cow that has two alleles for a red coat is homozygous (bb).

Detailed explanation-5: -The gene that is always expressed is called the dominant gene, while the gene that is silent is called recessive. Only the dominant gene will be expressed in the organism’s phenotype, but the organism will still be a carrier for the recessive gene.