Question

Hargobind Khorana is known for
A. Discovery of DNA
B. Discovery of DNA ligase
C. Discovery of tRNA
D. Synthesis of proteins

Answer 1

Hint: Hargobind Khorana was a biochemist who won the Nobel prize for Medicine in the year 1968. He was the first scientist to synthesize oligonucleotides artificially. Oligonucleotides are short strands of DNA or RNA containing only a few nucleotides unlike polynucleotides.

Complete answer:
Let us know about the scientists and their discoveries. The DNA was first discovered by James Watson and Francis Crick. Watson is however considered as the father of DNA and was awarded the Nobel prize for his discovery. Hargobind Khorana was the scientist who produces RNA chains with the help of enzymes. He is the first scientist to produce synthetic genes using enzymes like ligase and polymerase. These are the enzymes which link the DNA together. Paul Zamecnik is the scientist who first discovered non coding RNA which is nothing but the tRNA. Palade along with other scientists discovered that ribosomes are the organelles that perform protein synthesis.

So by the above explanation, the correct answer is option B.

Note:
Hargobind Khorana is also known for the discovery of visual pigment called rhodopsin. His invention of the first synthetic gene led to the discovery of polymerase chain reaction and also these artificial genes were widely used in genetic engineering. Khorana along with Nirenberg discovered the genetic code.