A biology student in Trinidad crosses pea plants that are tall (TT) with pea plants that are short (tt). All F1 offspring are tall. When two F1 plants are crossed, what fraction of the F2 offspring are expected to be short?

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Question

A biology student in Trinidad crosses pea plants that are tall (TT) with pea plants that are short (tt). All F1 offspring are tall. When two F1 plants are crossed, what fraction of the F2 offspring are expected to be short?

Accepted Answer

1/4 — Award 1 mark for correct answer. The F1 generation are all Tt (heterozygous tall). When F1 × F1 (Tt × Tt), the offspring ratio is 3 tall : 1 short, so 1/4 are short (tt). A is incorrect because this would be the ratio in a testcross. B is incorrect because this is the fraction of tall plants. D is incorrect because recessive traits reappear in F2.

Answer

3/4

Answer

1/2

Answer

1/4

Answer

0

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