Question

State and explain Mendel’s second law of inheritance.

Answer 1

Hint: Mendel worked on Pisum sativum for 7 year and proposed the law of inheritance in living organisms. Mendel proposes two general rules: the first law or Law of dominance and the second Law or law of segregation.

Complete answer:
This law is based on the fact that the two factors of a character present in an individual do not get mixed up and both the traits are recovered as such in the F2 generation though one of these is not seen at the F1 stage. During gamete or spore formation of a pair separate or segregate from each other, so that a gamete carrier only one factor of a character. This ensures the purity of gametes. Of course, a homozygous parent produces all gametes that are similar while a heterozygous will produce two type gametes each having one factor with equal proportion. This law is universally applicable.
Mendel worked on Pisum sativum and told that it contains seven contrasting traits as pod color, seed shape, flower colour, pod colour, flower position, plant height, and told about recessive and dominant traits.

Note:
LAW OF DOMINANCE:- The law of dominance is used to explain the expression of only one of the parental traits in a monohybrid cross in the F1 and the expression of both in F2. It also explains the proportion of 3:1 obtained in F2 generation. This law is not universally applicable.