What is the difference between homozygous and heterozygous?

The distinction between homozygous and heterozygous is fundamental to understanding basic genetics. Homozygous means that an organism carries two identical alleles for a specific gene. For example, if a gene for flower color has two alleles, one for red and one for white, an organism that is homozygous would have either two red alleles (RR) or two white alleles (WW). This uniformity can lead to consistent expression of a trait.

On the other hand, heterozygous refers to having two different alleles for a gene. Continuing with the flower color example, if one allele is for red (R) and the other for white (r), then the organism is heterozygous (Rr). This can introduce genetic variation and possibly result in the expression of a dominant trait if one allele is dominant over the other.

Understanding these definitions is crucial in genetics, as it helps in predicting inheritance patterns, analyzing phenotypes, and conducting breeding experiments.