Q. Diameter of DNA is about:

175 160 NTA AbhyasNTA Abhyas 2020 Report Error

A

$24 A$

B

$20 A$

C

$34 A$

D

$30 A$

Solution:

The diameter of DNA is about $20$ Armstrong. Watson and Crick model of the double helix is a right-handed coiled DNA. The two strands are antiparallel and complementary to each other. Both strands of the DNA helix are joined by hydrogen bonds. The coiling of two strands creates major and minor grooves.