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NEETZoologyMolecular Basis of Inheritance

What is the pitch of the helix in the Double-helix structure of DNA?

Options

  1. AApproximately 0.34 nm
  2. BApproximately 1.0 nm
  3. CApproximately 3.4 nm
  4. DApproximately 10 nm

Correct answer

C. Approximately 3.4 nm

Step-by-step solution

The salient features of the Double-helix structure of DNA are as follows: (i) It is made of two polynucleotide chains, where the backbone is constituted by sugar-phosphate, and the bases project inside. (ii) The two chains have antiparallel polarity. It means, if one chain has the polarity 5'🡪3', the other has 3’🡪5'. (iii) The bases in two strands are paired through hydrogen bond (H-bonds) forming base pairs (bp). Adenine forms two hydrogen bonds with Thymine from opposite strands and vice-versa. Similarly, Guanine

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