Question

How would you determine the genotype of your short hair guinea pig, assuming that hair length is determined by one allele and is a dominant phenotype to long hair. Please show your work.

Answer 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