AP BIOLOGY

Detailed explanation-1: -They have the same phenotype but different genotypes. In horses, the gene for white hair (W) is dominant to the gene for non-white hair (w). A horse with genotype (WW) was crossed with a horse with genotype (ww).

Detailed explanation-2: -Test crosses help researchers determine the genotype of an organism when only its phenotype (i.e., its appearance) is known. A test cross is a breeding experiment in which an organism with an unknown genotype associated with the dominant phenotype is mated to an organism that is homozygous for the recessive phenotype.

Detailed explanation-3: -The two things a Punnett square can tell you are the genotypes and phenotypes of the offspring. A genotype is the genetic makeup of the organism. This is shown by the three genetic conditions described earlier (BB, Bb, bb). The phenotype is the trait those genes express.

Detailed explanation-4: -The ABO blood group antigens are encoded by one genetic locus, the ABO locus, which has three alternative (allelic) forms-A, B, and O. A child receives one of the three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes).