Question

A male rabbit that is homozygous dominant for long hair over short hair H and heterozygous for black fur over gray fur B is crossed with a female rabbit that is heterogeneous for both traits. Show the punnet square and the expected offspring and their proportions ( ratios and percentages for both genotype and phenotype)

Answer 1

First, we establish the phenotypes of the parents:

Male HHBb x HhBb Female

Genotypic ratios 2:4:2:2:4:2

- HHBB: 2 (12.5%)

- HHBb: 4 (25%)

- HHbb: 2 (12.5%)

- HhBB: 2 (12.5%)

- HhBb: 4 (25%)

- Hhbb: 2 (12.5%)

Hh/HH: Long hair

BB/Bb: Black fur

bb: Gray fur

Phenotypic ratios: 12:4

- Long hair/Black fur (HHBB, HHBb, HhBB, HhBb): 12 (75%)

- Long hair/Gray fur (HHbb, Hhbb): 4 (25%)