Which components form the backbone of DNA?

Which components form the backbone of DNA?

• A. Ribose and Phosphate
• B. Deoxyribose and Phosphate
• C. Glucose and Phosphate
• D. Deoxyribose and Sulfate

Answer: (B)

DNA's backbone is the sugar-phosphate framework that holds the molecule together. Each nucleotide contributes a deoxyribose sugar and a phosphate group, and these are linked by phosphodiester bonds to form a repeating sugar-phosphate chain. The sugar is deoxyribose, which lacks the 2' OH of ribose, contributing to DNA's stability and the long, stable double helix. The nitrogenous bases extend from this backbone and pair with the opposite strand, while the backbone itself remains outside the helix. So, the components that form the backbone are deoxyribose and phosphate. Glucose or sulfate don’t form the DNA backbone, and ribose is characteristic of RNA, not DNA.

DNA's backbone is the sugar-phosphate framework that holds the molecule together. Each nucleotide contributes a deoxyribose sugar and a phosphate group, and these are linked by phosphodiester bonds to form a repeating sugar-phosphate chain. The sugar is deoxyribose, which lacks the 2' OH of ribose, contributing to DNA's stability and the long, stable double helix. The nitrogenous bases extend from this backbone and pair with the opposite strand, while the backbone itself remains outside the helix. So, the components that form the backbone are deoxyribose and phosphate. Glucose or sulfate don’t form the DNA backbone, and ribose is characteristic of RNA, not DNA.