Question

Here, B represents the allele for black hair and b represents the allele for white hair. If both the rabbits crossed had genotype Bb, what will be the phenotypic ratio for the observable monohybrid crosses (complete dominance)?

Answer 1

The answer would be 3:1

Answer 2

If B represents the allele for black hair and b represents the allele for white hair then a cross between Bb and Bb will lead to the following kind of progenies.

Parental: Bb x Bb

F1 : BB Bb Bb bb

Genotypic ratio : 1:2:1

Phenotypic ratio : 3:1

The phenotypic ratio indicates that three of the four off springs will have black hair while one of the four off springs will have white hair.

Amongst 3 offsprings which have black hair, one will be homozygous dominant whereas other two which have black hair color will be heterozygous dominant.