Genotype

Genotype is the combination of alleles, different versions of the same gene, inherited from each parent.

For example, height in a pea plant is determined by two alleles. One is a dominant allele represented by an uppercase T, and the other is a recessive allele represented by a lowercase t.

When both alleles are the same, the organism is called homozygous. In this case, since both alleles are dominant, it is called homozygous dominant, which results in a plant with a tall stem.

If both are recessive, it is called homozygous recessive, resulting in a plant with a short stem.

If both dominant and recessive alleles are present, the organism is heterozygous. Here, the dominant allele determines the trait, producing a tall plant.

Beyond simple traits like plant height, genotype plays an essential role in complex traits influenced by multiple genes and environmental interactions. For example, human height involves numerous genes and factors such as nutrition.