When both genes are the same in one parent cell, it's called homozygous.

Here's a breakdown:

* Homozygous: Means having two identical alleles (versions) of a gene. For example, having two copies of the gene for brown eyes (BB).

* Heterozygous: Means having two different alleles of a gene. For example, having one copy of the gene for brown eyes (B) and one copy of the gene for blue eyes (b).

Let me know if you have any other questions!