Updated Genetics & Heredity

Punnett Square Calculator

Generate offspring genotype and phenotype probabilities from any Mendelian monohybrid cross.

Genotype Ratios Phenotype Probabilities Gamete Combinations

Genotype Cross & Probability Computation

Predicting Offspring Traits Through Mendelian Inheritance

Punnett squares are foundational tools in genetics, allowing researchers, students, and breeders to model how alleles combine when parents reproduce. The Punnett square calculator automates this process by generating genotype and phenotype probabilities for any monohybrid cross involving dominant or recessive alleles.

The Logic Behind Gamete Formation

Each parent contributes one allele from a pair, forming gametes. For example:

  • AA → all gametes carry A
  • Aa → half gametes carry A, half carry a
  • aa → all gametes carry a

The calculator cross-combines gametes from both parents to generate the full Punnett square.

Understanding Genotype and Phenotype Ratios

Once gametes combine, offspring genotypes can be counted to produce probabilities. For a classical heterozygous cross:

  • Aa × Aa → 25% AA, 50% Aa, 25% aa

Phenotypes depend on dominance:

  • AA → dominant phenotype
  • Aa → dominant phenotype
  • aa → recessive phenotype

Applications Across Biology and Genetics

  • Predicting inherited traits
  • Understanding dominance relationships
  • Modeling genetic diseases
  • Plant and animal breeding programs
  • Teaching Mendelian inheritance concepts

Best Practices When Interpreting Punnett Squares

  • Use consistent dominance notation (uppercase = dominant).
  • Ensure both parents’ genotypes are correctly identified.
  • Recognize that real-world inheritance may include incomplete dominance, linkage, or environment effects.

By using a structured Punnett square calculator, genetic predictions become clearer, reproducible, and easy to visualize.

FAQ

Punnett Square & Trait Probability Questions

Essential explanations for Mendelian genetics and inheritance modeling.

A Punnett square is a genetic diagram used to predict offspring genotype and phenotype ratios from known parental genotypes.

It cross-combines alleles from each parent to produce all possible offspring genotypes and calculates probability percentages.

The calculator supports Mendelian monohybrid crosses with dominant and recessive alleles.

Yes. Based on allele dominance, the tool computes phenotype ratios automatically.

Yes. Uppercase indicates a dominant allele (A), while lowercase is recessive (a).

This version supports autosomal traits only. A sex-linked version can be generated if needed.

Yes. Classical Mendelian inheritance assumes each allele is inherited independently with equal probability.

This version is monohybrid only, but a dihybrid Punnett square calculator can be produced on request.

Any diploid organism that follows Mendelian inheritance patterns, including plants, animals, and humans.

A standard Aa × Aa cross produces a 3:1 phenotype ratio and 1:2:1 genotype ratio.