What does it mean to be heterozygous?

Being heterozygous refers to an organism having two different alleles of a gene. Alleles are versions of a gene that may produce different traits. When an organism has two different alleles for a particular gene, this heterozygosity can lead to varying phenotypic outcomes depending on the dominance relationship between the alleles.

For instance, if one allele is dominant and the other is recessive, the dominant trait will typically be expressed in the phenotype. This genetic variation among the alleles can contribute to the diversity of traits observed in a population.

In contrast, having two identical alleles of a gene is termed homozygous. The statement about one dominant and one recessive allele also applies to heterozygous conditions, but it is not a complete definition as heterozygosity does not exclusively imply the presence of a dominant and a recessive allele, since both alleles could be different but neither is strictly dominant or recessive. Lastly, having more than two alleles of a gene describes a situation often seen in populations, such as with blood types, but it does not pertain to individual heterozygous genotypes. Thus, the concept of being heterozygous centers specifically on having two different alleles