How many $H$-bonds are present between $G$ and $C$ in the structure of $DNA$?

In $DNA$,$20 \%$ of the bases are adenine. What percentage of bases are pyrimidines (in $\%$)?

If the sequence of one strand of $DNA$ is $5^{\prime}-ATGCATCG-3^{\prime}$,find the sequence of the complementary strand in the $5^{\prime} \rightarrow 3^{\prime}$ direction.

What would happen if histones were to be mutated and made rich in acidic amino acids such as aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?

Select the appropriate option for Transposons.

Describe the structure of $DNA$ as proposed by Watson and Crick.