the DNA double helix is coiled in a right-handed fashion where the pitch of the helix is 3.4 nm . This pitch represents the length of one full turn of the helix . Because there are approximately 10 base pairs in each turn, the calculated distance between consecutive base pairs is roughly 0.34 nm . Mastering these precise structural dimensions is a high-priority strategy for medical aspirants, as NCERT textbooks serve as the definitive primary source for approximately 95% of NEET Biology questions .