Question

By which of the following bonds are the nucleotides of DNA attached?

• A. Hydrogen
• B. Covalent
• C. Electrovalent
• D. All of these

Hint:

Covalent bonds connect the nucleotides in DNA, while hydrogen bonds hold the complementary base pairs together.

Answer 1

The Correct Option is B

Step 1: Recall nucleotide bonding in DNA.
The nucleotides in DNA are attached through covalent bonds, forming the backbone of the DNA strand.
Step 2: Review the options.
- Hydrogen bonds form between complementary base pairs (A-T and C-G), but the nucleotides are connected by covalent bonds.
- Covalent bonds form the sugar-phosphate backbone, connecting the nucleotides in a DNA strand.
- Electrovalent bonds are not involved in nucleotide bonding in DNA.
- Option (D) "All of these" is incorrect since only covalent bonds are involved in nucleotide bonding.
Step 3: Conclude.
The nucleotides in DNA are connected by covalent bonds, making option (B) the correct answer.
Final Answer: \[ \boxed{\text{Covalent}} \]