Barbara McClintock is famous for her work on

Assertion $(A) :$ The distance between two polynucleotide chains in $\text{dsDNA}$ remains constant.
Reason $(R) :$ Always a purine comes opposite to pyrimidine or vice versa.

With which nitrogenous base does $Adenine$ pair?

Which one of the following statements about Histones is wrong?

Watson and Crick are known for their discovery that $DNA$

$A$ gene is made up of