Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

Alleles produce the opposite and contrasting phenotypes. When two alleles of a gene are identical, they are homozygous, can be either dominant (AA, BB) or recessive (aa, bb) and when two different alleles, the individual is heterozygous and are made up of one dominant and one recessive allele (Aa, Bb). In heterozygous condition, the dominant allele is able to express and the recessive allele is hidden and the recessive condition is expressed in homozygous condition only.