Question

Using a Punnett Square, work out the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.

Answer 1

In the given figure, it is quite clear that it is a test cross of a heterozygous male with a homozygous female. In the F1 generation following phenotypic feature are observed:

1. Half of the progeny are Heterozygous Tall (Tt)
   
2. Another half of the population is Homozygous short (tt)
   

Hence the ratio for phenotypic features is same as genotype ratio, which is 2:2 or 1:1