Explain the law of dominance with an example.

The law of dominance states that when two contrasting alleles for a trait are present in an organism, only one allele (the dominant allele) is expressed, while the other (the recessive allele) remains hidden.

For example, in pea plants, the trait for tall height (T) is dominant over the trait for dwarf height (t). When a pure tall plant (TT) is crossed with a pure dwarf plant (tt), all offspring in the first generation (F1) have the genotype (Tt) and appear tall.

Although the recessive allele (t) is present, it does not express itself in the presence of the dominant allele (T).

Thus, the law of dominance explains why only one trait is visible when contrasting alleles are present together.