Monohybrid vs Dihybrid Cross
To study how genes work and how certain traits are inherited from the parents and grandparents, there are two types of breeding methods used; the monohybrid and dihybrid cross. The only difference between monohybrid and dihybrid crosses is the number of traits being looked into. A monohybrid cross is when the offspring of homozygous parents that only differ on a single trait are bred to come up with the second generation. On the other hand, a dihybrid cross is pretty similar to a monohybrid cross except that the parents of the first generation differ in two traits.
An example of a monohybrid cross would be crossing two animals whose parents are large and small. The result would be a ratio of 3:1 with more of the offspring exhibiting the dominant trait. For a dihybrid cross, imagine breeding the offspring of two animals; one of which is large and fat while the other is small and lean. The resulting ratio would be 9:3:3:1 with 9 exhibiting 2 dominant traits, 6 exhibiting 1 dominant and 1 recessive trait, and only 1 exhibiting both recessive traits.
A monohybrid cross is useful in learning the dominance of certain traits while a dihybrid cross is useful in studying how the traits are assorted across the second-generation offspring. No trait is lost, and you always get the full combination of traits represented. Although the practice probably preceded the science, dihybrid crossing has some very real applications. Farmers have been crossing animals with two traits in order to get the best possible combination. Imagine the example above was a farm animal like a cow or a pig. The farmer would cross a big and fat animal to a small and lean animal in the hopes of getting an animal that is both big and lean. This gives them the most amount of meat which they will then sell.
Summary:
1.A monohybrid cross is a cross between first-generation offspring of parents who differ in one trait while a dihybrid cross is a cross between first-generation offspring of parents who differ in two traits.
2.A monohybrid cross is useful in determining the dominance of genes while a dihybrid cross is useful in studying the assortment of the offspring.
3.A dihybrid cross is used to create a specimen with desirable traits.