Which of the following represents the simplified version of a nucleoside?

What are nucleic acids? Mention their two important functions.

In both $DNA$ and $RNA$,the heterocyclic base and phosphate ester linkages are at which positions of the sugar molecule?

$DNA$ 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.

Mutation of $DNA$ occurs due to changes in the sequence of one of the following:

The structure of the nitrogen-containing heterocyclic base given below represents: