Which statement describes the five-carbon sugar found in nucleotides?

Which statement describes the five-carbon sugar found in nucleotides?

• A. It is a five-carbon sugar
• B. It is a six-carbon sugar
• C. It is a two-carbon sugar
• D. It does not include sugars

Answer: (A)

Nucleotides are built with a five-carbon sugar, a nitrogenous base, and a phosphate group, so the sugar component is a pentose. In DNA the sugar is deoxyribose, and in RNA it’s ribose, both of which have five carbons. That’s why describing the sugar as a five-carbon sugar is the correct idea. The other options would imply the sugar is a different size or absent altogether, which doesn’t fit how nucleotides are structured.

Nucleotides are built with a five-carbon sugar, a nitrogenous base, and a phosphate group, so the sugar component is a pentose. In DNA the sugar is deoxyribose, and in RNA it’s ribose, both of which have five carbons. That’s why describing the sugar as a five-carbon sugar is the correct idea. The other options would imply the sugar is a different size or absent altogether, which doesn’t fit how nucleotides are structured.