Question

Which bonds are indicated by X and Y in the given diagram?

• A. X - Glycosidic bond
  Y - Hydrogen bond
• B. X - Phosphodiester bond
  Y - Hydrogen bond
• C. X - Glycosidic bond
  Y - Phosphodiester bond
• D. X - Phosphodiester bond
  Y - Glycosidic bond

Answer 1

The correct option is B X - Phosphodiester bond

Y - Hydrogen bond

• A phosphodiester bond occurs when exactly two of the hydroxyl groups in phosphoric acid react with hydroxyl groups on other molecules to form two ester bonds.
  
• Guanine and cytosine make up a nitrogenous base pair because their available hydrogen bond donors and hydrogen bond acceptors pair with each other in space. Guanine and cytosine are said to be complementary to each other.

So, the correct answer is 'B'.