A red four o'clock flower (RR) is crossed with a white four o'clock flower (WW), and the resulting F1 offspring are all pink (RW). If two of the pink offspring are crossed, what proportion of genotypes would you expect to see in the F2 generation?

A. 1 RW: 2 RR: 1 WW
B. 2 RR: 1 RW: 1 WW
C. 1 RR: 2 RW: 1 WW
D. 4 RR: 0 RW: 0 WW
E. 2 RR: 0 RW: 2 WW

The expected proportion of genotypes from a cross of two pink four o'clock flowers (RW) is a 1 RR : 2 RW : 1 WW genotypic ratio, corresponding to 1 red : 2 pink : 1 white phenotypic ratio in the F2 generation. Therefore the correct answer is option C

When two pink four o'clock flowers (RW) are crossed with each other, the expected proportion of genotypes in the F2 generation can be calculated using a Punnett square. Since the flowers exhibit incomplete dominance, where the red (R) and white (W) alleles are neither dominant nor recessive, the heterozygous condition results in pink flowers. The Punnett square would look as follows:

RW (male) gametes: R, W
RW (female) gametes: R, W

Crossing these gametes results in:

RR (red)
RW (pink)
WR (pink)
WW (white)

These outcomes give us a progeny ratio of 1 red (RR): 2 pink (RW or WR): 1 white (WW), which correspond to the genotypic ratio of 1 RR : 2 RW : 1 WW as seen in option C.