Question

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3:1. If the allele are designated (R & r) receptively. What is the probable genotypes of the round seeds which produced F1?

Answer 1

The answer would be RR and Rr
Since there were more round seeds (3:1 ratio), round seeds would be dominant and therefore be represented by the CAPITAL R.

Answer 2

The probable genotype of round seeded pea plant would be (Rr). The 3:1 ratio of round seeds to wrinkled seed indicates that round shape of seed is dominant over d wrinkle shape of seed. It means round seed allele would be (R) and wrinkle seed would be (r). Thus, when pure round seed plants (RR) is cross with pure wrinkled seed plant (rr), all the offspring in F1 will be round seeded pea plant according to Mendel’s law of dominance. The F1 plants will be hybrid and their genotype will be (Rr).