Question

This Punnett square shows flower color inheritance in snapdragons in an F1 generation. R is red and r is white.

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What would you expect the ratio of red flowers to pink flowers to white flowers to be in the F2 generation when two of these F1 offspring are crossed?


All pink


1 red: 2 pink: 1 white


9 red: 3 pink: 1 white


4 red: 1 white

Answer 1

1 red : 2 pink : 1 white

Rr × Rr gives genotypes 1/4 RR (red), 1/2 Rr (pink, incomplete dominance), 1/4 rr (white) — a 1:2:1 phenotypic ratio.