What is the structural difference between DNA and RNA?

What is the structural difference between DNA and RNA?

• A. DNA is single-stranded, while RNA is double-stranded
• B. DNA is double-stranded, while RNA is single-stranded
• C. DNA uses uracil and RNA uses thymine
• D. DNA has ribose sugar and RNA has deoxyribose

Answer: (B)

DNA is double-stranded, while RNA is usually single-stranded. In DNA, two polynucleotide chains wind together into a double helix and run antiparallel, with complementary base pairing (A pairs with T, G with C) that stabilizes the molecule and enables precise copying during replication. RNA tends to exist as a single strand and can fold into various shapes by intramolecular base pairing, which supports its diverse roles in the cell. Some differences highlighted in other descriptions—such as thymine versus uracil or the sugar component—reflect chemical composition rather than the basic structural arrangement; DNA uses thymine and deoxyribose, while RNA uses uracil and ribose.

DNA is double-stranded, while RNA is usually single-stranded. In DNA, two polynucleotide chains wind together into a double helix and run antiparallel, with complementary base pairing (A pairs with T, G with C) that stabilizes the molecule and enables precise copying during replication. RNA tends to exist as a single strand and can fold into various shapes by intramolecular base pairing, which supports its diverse roles in the cell. Some differences highlighted in other descriptions—such as thymine versus uracil or the sugar component—reflect chemical composition rather than the basic structural arrangement; DNA uses thymine and deoxyribose, while RNA uses uracil and ribose.