Question

Explain the Law of Dominance using a monohybrid cross.

Answer 1

The law of dominance states that when a pair of alleles or allelomorphs are combined in an F₁ hybrid, only one of them expresses itself, hiding the expression of the other. A monohybrid cross was used to investigate the simultaneous inheritance of a single pair of Mendelian components. A Monohybrid cross is one that considers only different versions of a single character. The feature that occurred in the F₁ generation was referred to as dominant, whereas the trait that did not appear in the F₁ population was known as recessive.

Thus, when a pair of alleles come together in an F₁ hybrid, only one of them expresses itself, hiding the expression of the other entirely. In the above example, in the Tt - F₁ hybrid (tall), only ‘T’ expresses itself as dominant, while ‘t’ remains hidden as recessive. This instance illustrates and indicates the law of dominance.