In Mendel's monohybrid crosses, homozygous refers to an organism that has two identical alleles for a particular trait. For example, if we consider a trait governed by a single gene with two possible alleles (let's say "A" for dominant and "a" for recessive), a homozygous individual could be either:
- Homozygous dominant (AA), having two copies of the dominant allele.
- Homozygous recessive (aa), having two copies of the recessive allele.
In contrast, a heterozygous individual would have one dominant allele and one recessive allele (Aa). Mendel's experiments with pea plants often involved observing the inheritance patterns of traits between homozygous and heterozygous plants to understand how traits are passed down through generations.