Question

A pea plant parent having violet-coloured flowers with unknown genotype was crossed with a plant having white-coloured flowers. In a progeny, 50% of the flowers were violet and 50% were white. The genotypic constitution of the parent having violet-coloured flowers was
A. Homozygous
B. Merozygous
C. Heterozygous
D. Hemizygous

Answer 1

Hint: Test cross is the cross which is done to discover the genotype of parents. For instance the F1​ hybrid had yielded 50% violet flowers as well as 50% white flowers; it is a clear case of heterozygous parents that means the genotypes of parents are Cc and cc.

Complete answer:
> Option A: Homozygous is a term that refers to a particular gene that has identical alleles on both homologous chromosomes. It is described by two capital letters (XX) for a dominant trait, whereas two lowercase letters (xx) are used to donate for a recessive trait.

> Option B: Merozygote is a state in which a cell, usually a bacterial, is temporarily partial diploid which as a result of DNA transfer processes like conjugation.

> Option C: Heterozygous term refers to having inherited different forms of a particular gene from each parent. A heterozygous genotype stands for contrast to a homozygous genotype.

> Option D: Hemizygous is a condition where only one copy of a gene or DNA sequence is present in diploid cells. That is in Males are hemizygous for most genes on sex chromosomes, having only one X along with one Y chromosome.

Hence, the correct answer is option (C).

Note: If the two alleles are identical to each other then they are Homozygous whereas Heterozygous can be different at one point in the gene, and it can be as dozens of different points in the gene.