In a given $DNA$ segment,the number of nucleotides of guanine is $75$ and those of thymine is $75$. The total number of nucleotides in the segment will be:

The segment of $DNA$ which acts as the instrumental manual for the synthesis of the protein is:

$DNA$ was first discovered by ......

Which of the following are the complementary base pairs found in the structure of $DNA$?

In a $DNA$ molecule, the percentage of cytosine is $28\%$. Calculate the percentage of adenine. (in $\%$)

Read the following statements and choose the set of correct statements:
$(a)$ Euchromatin is loosely packed chromatin
$(b)$ Heterochromatin is transcriptionally active
$(c)$ Histone octamer is wrapped by negatively charged $DNA$ in nucleosome
$(d)$ Histones are rich in lysine and arginine
$(e)$ $A$ typical nucleosome contains $400 \ bp$ of $DNA$ helix
Choose the correct answer from the options given below: