Q. One turn of the helix in a B-form DNA is approximately :
A) 20 nm
B) 0.34 nm
C) 3.4 nm
D) 2 nm
Explanation
[Solution from source] B-DNA has about 10 base pairs per turn with 0.34 nm between pairs, so one turn (pitch) is about 3.4 nm. 0.34 nm is the distance between adjacent base pairs, and 2 nm is the helix diameter. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.