Question

Which Indian molecular biologist was awarded the Nobel Prize for the discovery of genetic code?
a) Khorana
b) Ramakrishnan
c) Kashyap
d) Raman

Answer 1

Genetic code is the sequence of Nitrogenous bases on mRNA which directs the sequence of amino acids during protein synthesis. There are $64$ codons out of which $61$ codons code for $20$ amino acids; $3$ of them are stop codons and do not code for amino acids. Change in even a single codon causes mutation in DNA. The tRNA carries a particular amino acid to the site of translation by recognizing the codon on mRNA.

Complete answer:
Khorana: Providing proof that codon is a triplet, Har Gobind Khorana developed a chemical method and synthesized RNA molecules with defined combinations of bases (homopolymers and copolymers). He was a biochemist and shared a Nobel Prize for his role in deciphering the genetic code in 1968.
Option (a) is correct.
Ramakrishnan: Indian-born British-American structural biologist who shared the $2009$ Nobel Prize in Chemistry, "for studies of the structure and function of the ribosome".
Option (b) is incorrect.
Kashyap: He wasn’t one of the scientists who received the Nobel prize.
Option (c) is incorrect.
Raman: In $1930$, C.V. Raman won the Nobel Prize in Physics "for his work on the scattering of light and for the discovery of the effect named after him.
This option (d) is incorrect.

Hence the correct answer is option (a).

Note:
There are some properties of genetic code, which are as follows:
The codon is triplet, and is nearly universal.
Out of $64$, $3$ codons that function as stop codons are- UAA, UGA and UAG. These terminate the protein synthesis.
Codons are degenerate, i.e., Same amino acids can be coded by more than one codon.
They are unambiguous and specific i.e., one codon codes for only one amino acid.
There is no punctuation and the codons in mRNA are read in a contagious manner.