LIFE SCIENCE

Detailed explanation-1: -The homozygous dominant RRYY will produce only one type of gametes which is RY. The other parent is heterozygous containing both dominant and recessive alleles that will produce 4 types of gametes, they are RY, rY, Ry and ry. The Punnett square will give four types of genotype, viz., RRYY, RrYY, RRYy, and RrYy.

Detailed explanation-2: -Test cross The cross between the progeny of F1 and the homozygous recessive parent is called test cross.

Detailed explanation-3: -In a dihybrid cross, the parents carry different pair of alleles for each trait. One parent carries homozygous dominant allele, while the other one carries homozygous recessive allele. The offsprings produced after the crosses in the F1 generation are all heterozygous for specific traits.