Question

Choose the correct answer from the alternatives given:
The part of a DNA molecule that varies among DNA molecules is

• A. Glycerol attachments
• B. Nitrogenous bases
• C. Sugars
• D. Phosphates

Answer 1

The correct option is B Nitrogenous bases

Nucleotides are the basic unit of DNA. It is composed of three major parts, namely a sugar molecule, a nitrogenous base and a phosphate molecule.

DNA contains four different bases i.e. adenine, guanine, cytosine and thymine. DNA is formed when different types of nucleotides join together. A nucleotide may contain any of the bases. But the sugar molecule (deoxyribose) and the phosphate remains the same. Thus, the part of the DNA molecule that varies among DNA molecules is nitrogenous bases.

Hence, the correct answer is 'Nitrogenous bases'.