How to Complete a Dihybrid Punnett Square

Animated Explainer Video

Predict the results of a two-trait cross

Punnett squares work by crossing parental genotypes. Punnett squares can also be used to determine the probability of the genotypes and phenotypes of two traits inherited by an offspring. These crosses, called dihybrid crosses, are very similar to monohybrid crosses. However, the major difference being that they predict the inheritance of two genes rather than one singular gene. For example, rather than just analyzing the probability of inheriting a certain seed color in pea plants, a dihybrid cross can determine the probability of inheriting a certain seed color and seed shape.

While these crosses are completed in a similar manner to monohybrid crosses, there are important differences in the process that must be accounted for. Turn on video captions for detailed instructions.