Q. In a double helix of DNA molecule of 10 coils, if there are 30 adenine nitrogen bases, what is the number of guanine nitrogen bases?
A) 30
B) 60
C) 70
D) 80
Explanation
Total number of coils in a DNA molecule=10. We know that total number of nitrogen bases are present in a coil=20 (or 10 pairs). Thus, total number of nitrogenous base is 200. Out of these, 30 are adenine thus, according to Chargaff’s rule guanine should be 70 in number.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.