Question

According to the law of Independent Assortment in a dihybrid cross
a. There are four genotypes in F2
b. F2 contains 16 phenotypes
c. There is a single individual which is a homozygous recessive for both the characters
d. It is not possible to forecast the different phenotype

Answer 1

Hint: The law of Independent Assortment states that during the formation of gametes, one pair of trait segregates from another pair of trait independently. This law was given by Gregor Mendel in 1865. The ratio of the dihybrid cross is 9:3:3:1. The Law of Independent Assortment states is also known as the third law of Mendel or the third law of inheritance.

Complete answer:
- Mendel conducted an experiment of a dihybrid cross on a pea plant and gave the third law of the principle of inheritance. It is called the law of independent assortment.
- This law states that in the F2 generation 16 progeny are obtained. Out of this 16 progeny, 4 types of phenotypes and 9 types of genotypes appear.
- In 16 progenies, 6 progeny shows genetic recombinations, 1 homozygous dominant for both characters(AABB) 8 are heterozygous dominant for round and yellow, and one progeny is homozygous recessive for both characters(aabb).
- According to this law, during the formation of gametes genes separate independently from one another.
- The Law of independent assortment can be observed in Prophase I in the pachytene stage.
- A mendelian dihybrid cross is the best example of an independent assortment. The combination of round green and wrinkled yellow describes that genes for the color of the seed and shape of the seed are assorted independently.

Hence, the correct answer is option (C).

Additional information:
- The ratio of the cross is 9:3:3:1.
- In this cross, 9 offspring are yellow and round.
- 3 are yellow and wrinkled
- 3 are green and round.
- 1 is green and wrinkled.

Note: The Law of independent assortment states that during the gamete formation, one pair of traits separate from another pair of traits, independent of each other. Independent assortment of genes is important because it produces new genetic combinations that increase genetic variations within a population. It takes place with linked genes or genes that share the same chromosome.