Dihybrid cross proves the law of independent assortment. Mendel found that each pair of alleles segregates independently of the other pairs of alleles during gamete formation. This is known as Law of independent assortment. Dihybrid cross - cross between two parents that differ by two pairs of alleles (AABB X aabb). The formation of gametes is an application of this law.

Dihybrid cross is a type of genetic cross where two traits are studied simultaneously. It involves the breeding of organisms that differ in two characteristics. The progeny of such a cross are called dihybrids.

The law of independent assortment is one of the basic laws of genetics. It states that the inheritance of one trait is not influenced by the inheritance of another. The law of independent assortment is based on the observation that the alleles of different genes segregate independently of each other during the formation of gametes.

Explanation:

The law of independent assortment is proved by dihybrid cross. In a dihybrid cross, two traits are studied simultaneously. For example, if we take two pea plants that differ in two traits, flower color (purple or white) and seed shape (round or wrinkled), we can perform a dihybrid cross. Let's denote the dominant allele for flower color as P and the recessive allele as p. Similarly, let's denote the dominant allele for seed shape as R and the recessive allele as r. The parental plants can be represented as:

Purple round (PPRR) x white wrinkled (pprr)

When these two plants are crossed, the F1 generation will be all purple and round because both the dominant alleles (P and R) are present in the parental plants. The F1 plants can be represented as:

PpRr

When we cross two F1 plants, we get the F2 generation. According to the law of independent assortment, the alleles of different genes segregate independently of each other during the formation of gametes. This means that the alleles of flower color (P and p) and seed shape (R and r) will segregate independently of each other. Therefore, the possible gametes that each F1 plant can produce are:

PR, Pr, pR, pr

When we combine these gametes to form the F2 generation, we get the following results:

Purple round (P_R_) = 9/16
Purple wrinkled (P_rr) = 3/16
White round (ppR_) = 3/16
White wrinkled (pprr) = 1/16

The ratio of the phenotypes in the F2 generation is 9:3:3:1, which is the same as the ratio predicted by the law of independent assortment. This proves that the law of independent assortment is correct.

Conclusion:

Dihybrid cross proves the law of independent assortment. It shows that the inheritance of one trait is not influenced by the inheritance of another. The alleles of different genes segregate independently of each other during the formation of gametes.