Question

In a given species of flowering plant, the colour of the seeds is exclusively determined by the colour of its seed coat. Seed coat colour in this species is governed by a nuclear gene with two alleles. The WHITE (W) allele is dominant over brown (w) allele. If a plant with brown seeds (ww) is crossed as a female with pollen from a white seed (WW) plant, what will be the seed colour and the genotype of the embryo in the resultant seeds obtained from this cross?

Answer 1

Seed color: brown, Embryo genotype: Ww

Answer 2

The seed coat color is determined by the maternal genotype because the seed coat is derived from the maternal tissue (integuments). The maternal plant is ww, so the seed coat genotype is ww, which results in brown seeds. The embryo's genotype is determined by the fusion of the male gamete (W from the WW parent) and the female gamete (w from the ww parent), resulting in a Ww genotype for the embryo.