Which of the following represents a heterozygous genotype?*rrAaYellow feathersRed and white spotted

The heterozygous genotype from the options given is "Aa".

Here's why:

A genotype is the set of genes an organism carries for a particular trait. In a diploid organism (like humans), each cell contains two copies of each gene - one from the mother and one from the father.

If the two copies are identical, the organism is homozygous for that gene. If the two copies are different, the organism is heterozygous for that gene.

In the options you provided, "rr" is homozygous recessive, because both copies of the gene are the same (and recessive). "Aa" is heterozygous, because the two copies of the gene are different - one is dominant (A) and one is recessive (a).

"Yellow feathers" and "Red and white spotted" are phenotypes (physical expressions of a genotype) rather than genotypes, so they don't apply to this question.