AP BIOLOGY

Detailed explanation-1: -Short hair is dominant which means it can express in both heterozygous(Hh) and homozygous condition(HH). If all the progeny have short hair, then the parents should have been either: HH x HH OR HH x Hh OR HH x hh.

Detailed explanation-2: -In guinea pigs, short fur (S) is dominant, and long fur (s) is recessive. A female guinea pig with short fur is mated with a male with long fur. Half of the guinea pigs in the litter have short fur, and the other half have long fur.

Detailed explanation-3: -Genetics One affects coat length. Guinea pigs which are homozygous for the dominant form of this gene (ie which have a pair of dominant genes) have short hair. Peruvians (and other long-haired breeds) are homogygous for the recessive form of the gene which causes the abnormally long hair growth.

Detailed explanation-4: -A cross (or mating) between two organisms where two genes are studied is called a DIHYBRID cross. The genes are located on separate chromosomes, so the traits themselves are unrelated.