Class 12th Biology 2017 Set1 Delhi Board Paper Solution

Question 25

State and explain the ‘law of independent assortment’ in a typical Mendelian dihybrid cross.

Answer

Law of independent assortment: The law states that when two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters.

In the dihybrid cross, the phenotypes

round yellow;     unwrinkled yellow;    Round green    and    wrinkled green appear in the ration of

   9                :          3                  :           3             :             1

Mendel proposed a second set of generalisation that we call Medel's law of Independent Assortment.



The Punnett square can be effectively used to understand the independent segregation of the two pairs of genes during meiosis. Linkage is the exception of law of independent assortment.

The production of eggs and pollen in the F, Rr, Yy plant. Fifty % of the gametes have the gene R and other fifty % have r segragation of 50% R and 50% r is independent from the segragation of 50% of Y and 50% of y.