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?

Rr and rr

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.

yes it is weird but true