How to Calculate Punnett Square
What is Punnett Square?
A Punnett square is a visual diagram to predict offspring genotype combinations from known parental genotypes. Created by Reginald Punnett around 1905.
Step-by-Step Guide
- 1Write one parent's gametes across the top, the other's down the side
- 2Fill each cell by combining corresponding alleles
- 3Count genotype frequencies from the completed grid
Worked Examples
Input
Aa × Aa
Result
AA, Aa, Aa, aa → 1:2:1 genotype · 3:1 phenotype
4 cells; AA=1, Aa=2, aa=1
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