Question

Which of the following statements is incorrect about DNA?

• A. Guanine is bonded with Cytosine with three H-bonds
• B. The two chains are coiled in a right handed fashion
• C. Backbone is constituted by sugar-phosphate
• D. A purine comes opposite to a purine only

Answer 1

The correct option is D A purine comes opposite to a purine only

A purine (A, G) pairs with pyrimidine (C, T) with the help of hydrogen bonds.
Guanine is bonded with cytosine with three H-bonds.
Backbone of DNA is constituted by sugar – phosphate.