The Difference Between Monohybrid Cross and Dihybrid Cross

Monohybrid Cross vs Dihybrid Cross

Monohybrid cross and dihybrid cross are two types of genetic crosses used in studying the inheritance of traits. They are similar in some aspects but differ in their complexity and the number of traits involved.

Monohybrid Cross: In a monohybrid cross, the genetic cross is performed between two organisms that are heterozygous for a single trait. This means that the parents differ in only one trait, such as flower color or seed shape. For example, if one parent has the genotype Aa and the other parent also has the genotype Aa, the offspring will inherit one allele from each parent resulting in a 1:2:1 genotypic ratio and a 3:1 phenotypic ratio.

Dihybrid Cross: In a dihybrid cross, the genetic cross is performed between two organisms that are heterozygous for two different traits. This means that the parents differ in two traits, such as flower color and seed shape. For example, if one parent has the genotype AaBb and the other parent also has the genotype AaBb, the offspring will inherit one allele from each parent for each trait resulting in a 1:2:1:2:4:2:1:2:1 genotypic ratio and a 9:3:3:1 phenotypic ratio.

The Differences:

• A monohybrid cross involves a single parent, while a dihybrid cross involves two parents.
• A monohybrid cross produces a single progeny, while a dihybrid cross produces two progeny.
• A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid only one.
• A monohybrid cross is performed for one generation, while a dihybrid cross is performed for two generations.
• A monohybrid cross results in a 1:2:1 genotypic ratio and a 3:1 phenotypic ratio of offspring, while a dihybrid cross gives a 1:2:1:2:4:2:1:2:1 genotypic ratio and a 9:3:3:1 phenotypic ratio.