Punnett Squares

Calculate genetic crosses from simple monohybrid to complex multi-gene scenarios.

What is a Punnett Square?

A Punnett square is a visual tool for predicting the genotypes and phenotypes of offspring from a genetic cross.

Basic Crosses

Monohybrid Cross (One Gene)

Cross two heterozygous parents: Aa × Aa

	A	a
A	AA	Aa
a	Aa	aa

Results:

• 25% AA (homozygous dominant)
• 50% Aa (heterozygous)
• 25% aa (homozygous recessive)

Phenotype ratio: 3:1 (dominant:recessive)

Using the API

curl -X POST http://localhost:8000/api/genetics/cross \
  -H "Content-Type: application/json" \
  -d '{
    "parent1_genotype": "Aa",
    "parent2_genotype": "Aa"
  }'

Using Zygotrix AI

Simply ask:

"What are the offspring of Aa × Aa?"

Complex Crosses

Dihybrid Cross (Two Genes)

Cross AaBb × AaBb:

Results:

• 9/16 dominant for both traits
• 3/16 dominant A, recessive B
• 3/16 recessive A, dominant B
• 1/16 recessive for both

Phenotype ratio: 9:3:3:1

Trihybrid and Beyond

Zygotrix supports multi-gene crosses:

curl -X POST http://localhost:8000/api/genetics/cross \
  -d '{
    "parent1_genotype": "AaBbCc",
    "parent2_genotype": "AaBbCc"
  }'

Inheritance Patterns

Complete Dominance

One allele completely masks the other:

• AA, Aa → Dominant phenotype
• aa → Recessive phenotype

Incomplete Dominance

Heterozygotes show intermediate phenotype:

• RR → Red flowers
• Rr → Pink flowers
• rr → White flowers

Codominance

Both alleles fully expressed:

• AB → Both A and B traits visible
• Example: Blood type AB

Examples by Trait

Eye Color (Simplified)

Parent 1	Parent 2	Offspring
BB × BB	All BB	All Brown
BB × bb	All Bb	All Brown
Bb × Bb	BB:Bb:bb = 1:2:1	3 Brown : 1 Blue
Bb × bb	Bb:bb = 1:1	1 Brown : 1 Blue

Coat Color in Animals

Genotype	Phenotype
BB, Bb	Black coat
bb	Brown coat

Calculation Performance

Cross Complexity	Calculation Time
Monohybrid (1 gene)	Under 10ms
Dihybrid (2 genes)	Under 20ms
Trihybrid (3 genes)	Under 50ms
5+ genes	Under 200ms

Powered by the C++ engine for maximum performance.

API Reference

See API: Genetics for full API documentation.