Here's why:
* Heterozygous: Means having two different alleles (versions of a gene) for a particular trait. For example, having one allele for brown eyes and one allele for blue eyes.
* Homozygous: Means having two identical alleles for a particular trait. This can be homozygous dominant (two dominant alleles) or homozygous recessive (two recessive alleles). For example, having two alleles for brown eyes or two alleles for blue eyes.