Describe monohybrid cross with a suitable example.

A monohybrid cross is a genetic cross between two organisms that differ in a single pair of contrasting traits.

For example, in pea plants, consider a cross between a pure tall plant (TT) and a pure dwarf plant (tt). The tall trait (T) is dominant over the dwarf trait (t).

In the first generation (F1), all offspring have the genotype (Tt) and appear tall because the dominant allele expresses itself.

When these F1 plants are self-crossed (Tt × Tt), the second generation (F2) shows three tall plants and one dwarf plant, resulting in a phenotypic ratio of 3:1.

This cross helps in understanding the inheritance of a single trait and demonstrates Mendel’s laws of dominance and segregation.