Question

One pure strain of pea plants developed by Mendel had yellow seeds and another strain had green seeds. All the offsprings from crosses between these two parental strains of plants had yellow seeds. In these plants, the allele for yellow seed colour is ______.

Options

• recessive to the allele for green colour

• dominant over the allele for green colour

• epistatic over other alleles

• expressed only in gametes

Answer 1

One pure strain of pea plants developed by Mendel had yellow seeds and another strain had green seeds. All the offsprings from crosses between these two parental strains of plants had yellow seeds. In these plants, the allele for yellow seed colour is dominant over the allele for green colour.

Explanation:

When Mendel crossed a pure strain with yellow seeds and another with green seeds, all offspring had yellow seeds, indicating that the yellow seed allele is dominant. The green seed colour allele is recessive and only appears when both alleles are green (homozygous recessive). Thus, yellow seed colour manifests in heterozygous offspring because its allele is dominant over the green allele.