$DNA$ consists of two polynucleotide chains. Each chain forms a right-handed spiral with how many bases in one turn of the spiral?

Which of the following is not a constituent of nucleic acids?

$DNA$ 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.

In a nucleoside,a base is attached at the $1^{\prime}$ position of the sugar moiety. $A$ nucleotide is formed by linking a phosphoric acid unit to the sugar unit of a nucleoside. At which position of the sugar unit is the phosphoric acid linked in a nucleoside to give a nucleotide?

Which base is present in $RNA$ instead of $Thymine$?

If one strand of $DNA$ has the sequence $ATGCTTGA$,what would be the sequence of its complementary strand?