Build your own genetic inheritance simulation. Select the inheritance model, enter parent genotypes, and see full probability distributions across all possible outcomes.
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Generated at traitgen.com, Free genetics education. Not medical advice.
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โ ๏ธ Educational only. Probability estimates based on genetic models, not medical advice.
The Punnett square, invented by Reginald Crundall Punnett in 1905, was originally designed to settle a debate about why blue-eyed chickens were not disappearing despite brown being dominant. It remains the most powerful simple tool for visualising genetic inheritance probabilities.
Genetic simulators solve probability matrices by mapping parental alleles to child combinations. Depending on the model chosen, the relationship between alleles varies: Mendelian features use simple dominant/recessive rules, co-dominant features express both alleles together, and X-linked traits reside exclusively on sex chromosomes.
Simple single-gene models where one dominant allele overrides a recessive counterpart, yielding a 3:1 phenotype ratio from hybrid crossings.
Both alleles express fully in the phenotype, as seen in ABO blood groups where A and B alleles are co-dominant and O is recessive.
Traits governed by genes on the X chromosome. Since males are XY, they express any recessive gene present on their single X chromosome.
A Punnett square calculates combinations: 1 parent with Aa and 1 with Aa yields 25% AA, 50% Aa, and 25% aa child probabilities.
It is a visual grid representing fertilization. Parent gametes (sperm/egg) are written along the top and side, and grid cells are filled with combining alleles to show child odds.
In dominant inheritance, one allele hides the other (e.g. Aa looks like AA). In co-dominant inheritance, both express equally (e.g. type AB blood expresses both antigens).
Boys are affected much more frequently because they have only one X chromosome. Girls have two X chromosomes, meaning a normal dominant allele on one can mask a recessive variant on the other.
Yes, as long as you know the basic genetic model and parent genotypes, this simulator calculates the mathematical probability distributions.