Question

A tall pea plant (TT) is crossbred with a short pea plant (tt). The following Punnett square shows the separated alleles for two pea plants.

Punnett square showing female parent across the top with a phenotype of tall and a genotype of TT and a male parent across the side with a phenotype of short and a genotype of tt. Inside the top left box 1 is written, inside the top right box 2 is written, inside the bottom left box 3 is written, inside the bottom right box 4 is written.

Which of the following shows the correct match of the box numbers and the genotype of the offspring?

Group of answer choices

1 = TT; 2 = TT; 3 = Tt; 4 = Tt

1 = TT; 2 = Tt; 3 = Tt; 4 = tt

1 = Tt; 2 = Tt; 3 = Tt; 4 = Tt

1 = TT; 2 = Tt; 3 = Tt; 4 = Tt

Answer 1

Correct answer: 1 = Tt; 2 = Tt; 3 = Tt; 4 = Tt.

Reason: TT can only contribute T gametes and tt can only contribute t gametes, so every offspring is Tt (heterozygous) and shows the tall phenotype (T is dominant).