Question

Bond present between two nucleotides on a single strand of DNA is:

• A. Phosphodiester bond.
• B. Hydrogen bond.
• C. Glycosidic bond.
• D. Covalent bond.

Hint:

Phosphodiester bonds form the sugar-phosphate backbone in a single DNA strand, while hydrogen bonds link the complementary bases between strands.

Answer 1

The Correct Option is A

Step 1: Bond formation in DNA. 
In a DNA strand, nucleotides are linked by phosphodiester bonds. This bond forms between the 3'-hydroxyl group of one nucleotide and the 5'-phosphate group of the next nucleotide, creating the sugar-phosphate backbone. 
Step 2: Explanation of other bonds. 
Hydrogen bond (Option B): Forms between complementary nitrogenous bases (e.g., A-T, G-C) in a double-stranded DNA, not within a single strand. 
Glycosidic bond (Option C): Links the sugar and nitrogenous base within a nucleotide. 
Covalent bond (Option D): A general term; phosphodiester bonds are a specific type of covalent bond. \[ \therefore \text{The correct answer is: Phosphodiester bond.} \]