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
B-DNA is helical structure with 20 Å diameter and the distance between the two base pairs is 3.4Å and there are 10 base in each turn or pitch (one round). Hence, one turn of the helix is approximately 34Å or 3.4 nm (10Å=1.0 nm).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.