Question

A gardener crosses tall true-breeding pea plants with short true-breeding ones. Tall plants are dominant to short ones. He collects the seeds to grow F1 plants and then allows them to self-pollinate to form an F2 generation. Which of the following describes the traits of the offspring correctly?

Answer 1

The ratio of the sizes of generation F2 will be 3:1 => 75% will be tall and 25% will be short

Answer 2

If you draw a Punnett square you can see the ratios. In the F1 or first filia generation they will all be tall because the tall trait masks the short one. The plants are all heterozygous tall with Tt as the genotype. If allowed to self pollinate the Tt x Tt will produce a 75% tall and 25% short phenotype. The genotype a will be Tt 50% TT 25% and tt 25%