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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.
Solution
When a heterozygous male tall plant (Tt) crosses with a homozygous dominant female tall plant (TT), we receive two types of gametes in males: half with T and half with t, while females only get one form of gamete, T.
The Punnett square shows that all of the progeny in the F1 generation are tall (Tt), with 50% homozygous tall (TT) and 50% heterozygous tall (Tt).
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