In a beetle species the red color is dominant over the white color. What is the genotype of any red beetle resulting from this species?

1Points
A
red and white alleles present on one chromosome

B
red and white alleles present on two chromosomes

C
a red allele present on both homologous chromosomes

D
a red allele present on at least one of two homologous chromosomes

It is given that in a beetle species the red color is dominant over the white color. Thus, in order to have a offspring of red color at least one of the two homologous chromosome must have red allele.

This can be further understood from the cross below -

Suppose one of the parent is homozygous red with genotype "RR" and other parent is homozygous white with genotype "rr"

If a cross is carried out between the two parents, the following offsprings will result -

RR x rr

Rr, Rr, Rr, Rr

Since there is no co dominance, thus the dominant allele will express itself completely and hence at least one of the homologous chromosome of offspring must have red color allele.