what is punnett square in science

A Punnett square is a tool used in genetics to predict the possible genotypes of offspring from a particular cross or breeding experiment. It is named after Reginald C. Punnett, who developed the approach in 1905. The Punnett square is a tabular summary of possible combinations of maternal alleles with paternal alleles, and it is used to determine the probability of an offspring having a particular genotype. The known genotypes of each parent are shown in the square to help predict the possible genotypes of their offspring. The Punnett square is typically applied in monohybrid crosses and dihybrid crosses, in which the theoretical outcomes are based on the assumptions of segregation and independent assortment of alleles according to Mendelian inheritance. The Punnett square is a visual representation of Mendelian inheritance. It is important to understand the terms "heterozygous", "homozygous", "double heterozygote" (or homozygote), "dominant allele" and "recessive allele" when using the Punnett square method. Phenotypes may be predicted with at least better-than-chance accuracy using a Punnett square, but the phenotype that may appear in the presence of a given genotype can in some instances be influenced by many other factors, as when polygenic inheritance and/or epigenetics are at work.