What occurs when two individuals with a homozygous recessive genotype mate?

When two individuals with a homozygous recessive genotype mate, the only alleles they can pass on to their offspring are recessive alleles. In genetics, a homozygous recessive genotype is represented as "aa," where "a" denotes the recessive allele.

Since both parents are "aa," they can only contribute "a" alleles to their offspring, resulting in all offspring being "aa" as well. This uniformity in inheritance means that every single offspring will inherit the recessive trait, leading them all to express the recessive phenotype. Thus, the correct answer reflects that all offspring from this mating will show the recessive phenotype due to the lack of dominant alleles in either parent's genotype.