Question

Which type of bond characterizes the primary structure of DNA?

• A. Hydrogen bond
• B. Ionic bond
• C. Phosphodiester bond
• D. Disulfide bond

Hint:

DNA backbone = Sugar + Phosphate
Nucleotides linked by → {Phosphodiester bonds}

Answer 1

The Correct Option is C

Concept:
DNA structure consists of several hierarchical levels. The primary structure refers to the linear sequence of nucleotides in the DNA strand.
Step 1:Understanding DNA components.
Each DNA nucleotide contains three components:

• A phosphate group
• A deoxyribose sugar
• A nitrogenous base

Step 2:Bond connecting nucleotides.
Adjacent nucleotides in the DNA strand are linked by phosphodiester bonds. These bonds connect the 3' hydroxyl group of one sugar molecule to the 5' phosphate group of the next nucleotide.
Step 3:Distinguishing from other bonds.

• Hydrogen bonds hold complementary bases together between two DNA strands.
• Disulfide bonds occur in proteins.
• Ionic bonds are not responsible for linking DNA nucleotides.

Conclusion:
Therefore, the bond that characterizes the primary structure of DNA is the phosphodiester bond.