Question

In a certain plant, the allele for red flower color (R) is dominant over the allele for white flower color (r). A cross is performed between a plant with red flowers and a plant with white flowers. The offspring are 47 plants with red flowers and 51 plants with white flowers. What are the genotypes of the parent plants?

Answer 1

Rr and rr

Step-by-step explanation:

The genotypes of the parents would be heterozygous red (Rr) and true-breeding white (rr).

Since the allele for the red flower color (R) is dominant over that of the white flower color (r), for a cross to produce both red and white flower color plants, the red parent must be heterozygous (Rr) and the white parent true-breeding (rr).

Rr x rr

Rr Rr rr rr

Rr = red

rr = white

If the red parents is true-breeding

RR x rr

Rr Rr Rr Rr

All their offspring would be red without any white flower color.

Hence, the genotypes of the parent are Rr and rr.