AP BIOLOGY

Detailed explanation-1: -In garden peas, yellow (Y) seed color is dominant to green (y). Because yellow and green are two different forms of the same gene (seed color), they are alleles. Use a Punnett square to show a cross between two heterozygous pea plants.

Detailed explanation-2: -In the case of Mendel’s peas, there are two different versions, or alleles, for seed color: yellow (Y) and green (y). Every plant will have two copies of each gene. We call this combination of alleles the plant’s genotype. The seed color we can observe is called the phenotype.

Detailed explanation-3: -An organism with two different alleles (Pp) is called a heterozygote. This results in three possible genotypes. [Figure 3] Relationship between allele, genotype, and phenotype.

Detailed explanation-4: -Since the Y (yellow) allele is dominant over the G (green) allele for pea plants, 100% of the YG offspring will have a yellow phenotype, as Mendel observed in his breeding experiments.

Detailed explanation-5: -How can two pea plants that have different genotypes for seed color be identical in phenotype? A. One of the two plants could be homozygous for the dominant allele, while the other could be homozygous for the recessive allele.