In a typical monohybrid cross the `F_(2)`-population ratio is written as `3:1` for phenotype but expressed as `1:2:1` for genotype. Explain with the help of an exmaple.

Explanation

A mononybrid cross is as follows:

Phenotypic ratio of smoth-seeded to wrinkled-seeded plants, `3:1`
Genotypic ratio-`1:2:1`,{1,homozygous: 2 Heterozygous: 1 Homozygous}