MONOHYBRID AND DIHYBRID CROSSES
In a monohybrid cross, each parent contributes two alleles, producing four possible combinations for the one trait.

Dihybrid crosses involve two traits. It is essential to recognize dihybrid (two-trait) crosses in order to solve them. Dihybrid crosses are predictions of how two traits will show up in the offspring produced by a mating between two parent organisms.

If two traits were studied in dihybrid crosses, how many alleles would be involved in a Mendelian dihybrid cross: one, two, three, or four? (Remember, there are two alleles per trait.)

The inheritance of two traits is studied in dihybrid crosses. For example, will the offspring of two guinea pigs have long black fur, short black fur, long brown fur, or short brown fur?