Question

The pitch angle of deflection between two successive base pairs in DNA double helix is

• A. ${20}^o$
• B. ${34}^o$
• C. ${36}^o$
• D. ${360}^o$

Answer 1

The correct option is C ${36}^o$

• The DNA in humans is a double helix. Pitch is the number of base pairs in one complete turn of the helix.
• There are 10 base pairs in 1 complete turn and the distance between 2 bases is 0.34nm.
• The deflection between two successive base pairs has a pitch angle of 36${}^o$.
  Thus the correct answer is option C.