Individual organisms carrying two identical alleles (for example TT or tt) are homozygotes, and those with dissimilar alleles(for example Tt) are called heterozygotes.
Homozygous vs Heterozygous
|It is pure for a trait and breeds true i.e., gives rise to similar homozygous individuals.||Heterozygous individual is seldom pure and produces offspring with different genotypes on selfing, eg., TT, Tt and tt on selfing of Tt individuals.|
|Both the alleles of a trait are similar, e.g., TT,tt||It carries dissimilar alleles, e.g., Tt|
|Homozygous individual can carry either dominant or recessive alleles but not both.||Heterozygous individual has both dominant and recessive alleles.|
|It produces one type of gametes.||It produces two types of gametes.|
|It does not show extra vigour.||The individual can show extra vigour called hybrid vigour or heterosis.|