Predict the genotypes and phenotypes of offspring from a genetic cross.
Parental Genotypes
Punnett Square Grid
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A
a
A
a
Cross Results
Enter valid parent genotypes (e.g., Aa, AA, aa)
Overview
A Punnett square is a diagram used to predict the genotypes of a particular cross or breeding experiment. Developed by Reginald Punnett, it provides a tabular summary of possible maternal and paternal allele combinations.
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Pro Tips
Use capital letters for dominant alleles (A) and lowercase for recessive alleles (a).
Heterozygous individuals (Aa) carry both a dominant and a recessive allele.
Homozygous individuals carry two of the same allele (AA or aa).
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Fun Facts
"The Punnett square only predicts probabilities, not guaranteed outcomes for every offspring."
"Mendel's law of segregation states that allele pairs separate during gamete formation."
"More complex crosses like dihybrid crosses use larger grids (4x4)."
"The terms 'dominant' and 'recessive' refer to the phenotype effect, not the allele's frequency in a population."
"Reginald Punnett created this tool in 1905, long after Mendel's initial work."
"Independent assortment assumes genes are on different chromosomes or far apart on the same one."
Formula: Probability = (Count of Genotype) / (Total Outcomes)
