Who proposed the double-helix structure of $DNA$?

Which part of $DNA$ acts as a messenger for the synthesis of proteins?

Which of the following is not a constituent of $RNA$?

$DNA$ 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.

$A$ nucleic acid,whether $DNA$ or $RNA$,gives on complete hydrolysis,two purine bases,two pyrimidine bases,a pentose sugar,and phosphoric acid. Nucleotides,which are intermediate products in the hydrolysis,contain:

Which of the following is correct about $H$-bonding in $DNA$?