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) respectively, what is the probable genotypes of the round seeds which were produced? a) rr & rrb) rr onlyc) rr & rrd) rr onlye) rr only

A) RR & Rr

Explanation:

In the given monohybrid cross, the obtained progeny expressed the round and wrinkled phenotype in 3:1 ratio respectively. Lets assume that the genotype of the parent plants was "Rr". A cross between Rr and Rr obtains progeny in following ratio=

Rr x Rr= 1/4 RR: 1/2 Rr: 1/4 rr.

Phenotype ratio= 3/4 round (1/4 RR and 1/2 Rr): 1/4 wrinkled (rr)

Therefore, the progeny with round seeds may be homozygous dominant (RR) or heterozygous dominant (Rr).