The base present in $DNA$,but not in $RNA$ is

$DNA$ fingerprinting is a technique used to identify individuals by their genetic makeup. It relies on the fact that the sequence of nucleotides in $DNA$ is unique to every individual,except for identical twins. The process involves isolating $DNA$,fragmenting it using restriction enzymes,separating the fragments via gel electrophoresis,and then using probes to visualize specific patterns ($DNA$ profiles). Uses: $1$. Forensic investigations for solving crimes. $2$. Determining paternity or maternity. $3$. Identifying genetic disorders and hereditary diseases.

What are the positions of $N$ atoms present in the purine ring of nucleic acids?

Which of the following bases is bicyclic?

Which of the following is not present in $DNA$?

When two nucleotides are linked together by a phosphodiester bond to form a dinucleotide,which carbon atoms of the pentose sugar of the nucleotides are involved in the linkage?