What defines a homozygous genotype?

A homozygous genotype is specifically defined as having two identical alleles for a particular gene. This means that the genetic makeup at that locus consists of either two dominant alleles or two recessive alleles. This uniformity can influence the phenotypic expression of traits, ensuring that the characteristics governed by that gene will consistently appear in the organism.

For instance, if an organism is homozygous dominant for a trait (such as AA), it will express that dominant trait. Similarly, if it is homozygous recessive (such as aa), it will express the recessive trait. This characteristic is fundamental in genetics as it helps predict the inheritance patterns of traits in offspring, particularly when crossed with organisms of different genotypes.

In contrast, a genotype with mixed alleles represents heterozygosity, which involves different alleles at the same locus, leading to potential variability in trait expression. Likewise, while expressing recessive traits may occur in homozygous recessive genotypes, it does not encompass the full definition of homozygosity. Lastly, stating that a homozygous genotype has no variation is misleading; while there are no allelic differences at a locus, the genetic variation exists in the greater context of the organism’s entire