AP BIOLOGY

Detailed explanation-1: -For example, a test cross between two organisms with the same genotype, Rr, for a heterozygous dominant trait will result in offspring with genotypes: RR, Rr, and rr. In this example, the predicted genotypic ratio is 1:2:1.

Detailed explanation-2: -If someone possesses both the dominant and recessive alleles for tongue rolling, we would write his or her genotype as “Rr”. The capital R shows that there is one dominant allele for tongue rolling, and the lower case r represents the other, recessive allele.

Detailed explanation-3: -A homozygous plant contains either of the following alleles for seed shape: (RR) or (rr). The (RR) genotype is homozygous dominant and the (rr) genotype is homozygous recessive for seed shape.

Detailed explanation-4: -Definition. A genotype is a scoring of the type of variant present at a given location (i.e., a locus) in the genome. It can be represented by symbols. For example, BB, Bb, bb could be used to represent a given variant in a gene.

Detailed explanation-5: -The genotype is represented by letter combinations, such as TT, Tt, and tt . When an organism has two of the same alleles for a specific gene, it is homozygous (homo-means “same") for that gene. An organism can be either homozygous dominant ( TT ) or homozygous recessive ( tt ).