Q. Which of the following is not relevant to the structure of double helical DNA?
A) The helix makes one completer spiral turn every 34Å
B) The diameter of the helix is 20Å
C) The distance between adjacent nucleotide is 3.4Å
D) Each strands of helix has a backbone made up of alternating ribose sugar and phosphate
Explanation
The Watson and Crick model shows that DNA is a double helix with deoxyribose sugar-phosphate back bone on the outside and paired bases on the inside. The planes of the bases are perpendicular to the helix axis. The planes of sugars are nearly right angles to those of the bases.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.