Calculate phenotype ratios and a Punnett grid for a one-, two-, or three-gene cross.
| Genes | – |
| Squares | – |
| Phenotype ratio | – |
Use this calculator for a Mendelian homework grid. Pick Parent 1 and Parent 2 from the list. Both parents must have the same number of genes: one gene (Aa) is a 2×2 square, two genes (AaBb) a 4×4, three genes (AaBbCc) an 8×8.
Gametes are formed by taking one allele from each gene. Each cell is the combination of one maternal and one paternal gamete. The phenotype ratio groups cells by complete dominance (A_ versus aa at each locus). Linked genes, lethals, incomplete dominance, epistasis, and sex linkage are not modelled.
Parent 1: First parent's genotype. Match the gene count of parent 2 (Aa with Aa, AaBb with AaBb, and so on).
Parent 2: Second parent's genotype, same number of genes as parent 1.
Genes: Number of loci in the cross.
Squares: Number of cells in the grid (4, 16, or 64).
Phenotype ratio: Reduced ratio of dominant versus recessive phenotypes at each locus, written as counts and codes such as 3 A_ : 1 aa.
Punnett square: The full grid, with parent 1 gametes on the left and parent 2 gametes across the top.
Related calculators