What is a Punnett square used for?

A Punnett square is a fundamental tool in genetics used to visualize genetic crosses and predict genotype ratios among offspring. By arranging the possible alleles from each parent on a grid, the Punnett square allows researchers and students to systematically explore the combinations of alleles that can result from a genetic cross. This visual representation helps in easily tracking the inheritance patterns and calculating the potential genotypes of the offspring, leading to a clear understanding of how traits may be passed on from one generation to the next.

While determining the phenotypic ratio of offspring is an important aspect of genetics, the primary function of the Punnett square is the visualization of allele combinations, which naturally leads to the prediction of genotype ratios. DNA sequencing and observing traits in nature involve broader and more complex methodologies beyond the simplicity and direct application of a Punnett square.