Question

Select the correct answer.

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?

A.
Three–fourths of the F1 and one–half of the F2 plants will be tall.
B.
All of the F1 and three–fourths of the F2 plants will be tall.
C.
Three–fourths of the F1 and all of the F2 plants will be tall.

Answer 1

Step-by-step explanation:

Let T = tall allele (dominant), t = short allele

True breeds are homo-zygous.

So the gardener is crossing TT with tt, with the resulting genotype of F1 all equal to Tt, i.e. all Tall hetero-zygous.

When the F1 pea plants are allowed to self-polinate, F2 results in Tt crossing with Tt, with the genotypes TT, Tt, tT and tt, and phenotypes 75% tall and 25% short, tall being dominant.