Question

A horticulturalist wants to produce geraniums with specific characteristics.

She knows that the trait of red flowers is governed by the allele R (RR and Rr) and the trait of white flowers is governed by the allele r(rr).

The horticulturalist crosses two geraniums from the F1 generation.

Look at the Punnett square to see this cross.

r r
R Rr Rr
r rr rr


Which ratio of red-to-white flowering plants would she expect to see in the phenotypes of the F2 generation?

Responses

1 red : 3 white

1 red : 3 white

3 red : 1 white

3 red : 1 white

2 red : 2 white

2 red : 2 white

all red

all red

Answer 1

The Punnett square shows 2 Rr (red) and 2 rr (white), so the expected phenotypic ratio is 2 red : 2 white (which is 1:1).