Punnett squares

A Punnett square is a diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles from the parents.

The letters represent alleles, which are different forms of a gene. Uppercase letters indicate dominant alleles, while lowercase letters indicate recessive alleles.

A homozygous genotype has two identical alleles for a trait, such as AA or aa.

A heterozygous genotype has two different alleles for a trait, such as Aa.

It means the organism has two dominant alleles for a trait, such as YY.

It means the organism has two recessive alleles for a trait, such as yy.

The phenotypic ratio in a monohybrid cross is typically 3:1 for dominant to recessive traits.

The genotypic ratio in a monohybrid cross is typically 1:2:1 for homozygous dominant, heterozygous, and homozygous recessive genotypes.

The phenotype of TT is tall.

The phenotype of Tt is tall.