Punnett Square Maker Punnett Squares
Create professional Punnett squares for genetics problems instantly. Describe the cross, and AI generates a labeled diagram with genotype and phenotype ratios.
Punnett Square Maker
Free to try ·
Your Punnett square will appear here
Describe the genetic cross and click Generate
Genetics Diagram Examples
Browse genetics diagram examples or generate your own above
Autosomal Dominant Inheritance
Autosomal dominant pedigree paired with Punnett square predictions.
Autosomal Recessive Carrier Cross
Carrier cross Punnett square showing 25% affected probability.
Sickle Cell Trait Cross
Sickle cell trait Punnett square for genetic counseling illustration.
X-Linked Inheritance
X-linked recessive Punnett square showing carrier mother cross.
Genetics Symbols Reference
Genetics notation reference with Punnett square conventions.
Dihybrid Cross Diagram
Dihybrid cross Punnett square showing the classic 9:3:3:1 ratio.
What is a Punnett Square?
A Punnett square is a grid used in genetics to predict the genotype and phenotype ratios of offspring from a specific cross between two parents. Each cell in the grid represents a possible allele combination. Punnett squares are named after Reginald Punnett and remain the standard teaching tool for Mendelian inheritance in biology courses worldwide.
Types of Punnett Square Crosses
- Monohybrid cross (2×2 grid) — predicts inheritance of one gene with two alleles
- Dihybrid cross (4×4 grid) — predicts inheritance of two genes simultaneously
- Test cross — crosses with a homozygous recessive to determine unknown genotype
- Incomplete dominance cross — heterozygote shows blended phenotype (1:2:1 ratio)
- Codominance cross — both alleles fully expressed in heterozygote (e.g., blood type)
- X-linked cross — accounts for sex-linked inheritance on the X chromosome
How to Use a Punnett Square
Identify the parent genotypes, then place one parent's alleles across the top and the other's down the left side. Fill each cell by combining the column and row alleles. Count the resulting genotypes to determine ratios. For a standard monohybrid cross between two heterozygotes (Aa × Aa), you get a 1:2:1 genotype ratio and 3:1 phenotype ratio.
Applications in Genetics
Punnett squares are used in genetic counseling to calculate the probability of offspring inheriting specific conditions. They help plant and animal breeders predict trait distributions. In education, they make abstract probability concepts concrete and visual. Combined with pedigree charts, they allow researchers to trace inheritance patterns across generations.
Frequently Asked Questions
More Biology Tools
BiologyPedigree Chart Maker
Create genetics pedigree charts showing inheritance patterns across generations.
ResearchAI Scientific Image Generator
Generate scientific illustrations and diagrams for research and education.
BiologyMitosis Diagram Generator
Create cell division diagrams showing mitosis stages for biology education.