Dihybrid crosses, also called two-factor crosses, predict the possible outcomes of genetic combinations of two traits, such as flower color and pod shape.

Video segment. Assistance may be required. Watch this video to see an introduction on how to complete a dihybrid cross.

Source: Dihybrid Punnett Square, MissKmetBioClass, YouTube

The steps to completing a dihybrid cross are the same as completing a monohybrid cross.

  1. Determine the dominant and recessive forms of the allele for the traits being analyzed, and then determine what letters to use to represent the genes.
  2. Determine the genotypes of the parents, and write down the cross.
  3. Determine the alleles of the gametes that would be produced during meiosis.
  4. Draw and set up the Punnett square. Put the genotype of the gametes produced by both parents on the top and left sides of the table.
  5. Fill in the middle of the Punnett square by combining the gametes.
  6. Analyze the results, and determine the genotypes and phenotypes of the offspring.

Interactive exercise. Assistance may be required. Let's look at an example. Click on the Next button to begin the animation.