Dihybrid Cross (Punnett Square)
Two independent traits with complete dominance (A over a, B over b). Choose each parent’s genotype per trait to see the 4×4 square and probabilities.
Mother’s Traits
No defaults selected (prevents backfilling). Pick both traits.
Father’s Traits
Choose both traits to populate gametes and the square.
Possibilities — Phenotypes
A_B_ —
A_bb —
aaB_ —
aabb —
Dominant phenotype needs at least one uppercase allele at that locus.
Possibilities — Genotypes
Shows every genotype observed among the 16 cells.
Step-by-step derivation
Select both traits for each parent to see the derivation…
Punnett Square (4×4)
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Each cell ≈ 6.25% when both parents are dihybrid (AaBb × AaBb). Duplicate headers reflect gamete probabilities for non-heterozygous parents.
References & Notes
- Four gametes per parent (e.g., AaBb → AB, Ab, aB, ab) under independent assortment.
- Complete dominance assumed (A over a; B over b). Phenotypes: A_B_, A_bb, aaB_, aabb.
- Percentages are counts over 16 cells (each cell equal probability when gametes are equally likely).