How can nucleotides found in $\mathrm{DNA}$ be discriminated from those found in $\mathrm{RNA}$?

• A. $\mathrm{DNA}$ nucleotides have uracil, while $\mathrm{RNA}$ nucleotides have thymine.
• B. $\mathrm{DNA}$ contains deoxyribose sugar, while $\mathrm{RNA}$ contains ribose sugar.
• C. $\mathrm{DNA}$ nucleotides are more stable than $\mathrm{RNA}$ nucleotides due to the presence of a hydroxyl group.
• D. $\mathrm{DNA}$ nucleotides are single-stranded, while $\mathrm{RNA}$ nucleotides are double-stranded.

Answer: (B)

Verified step by step guidance

1. Identify the sugar component in the nucleotide structure: DNA nucleotides contain deoxyribose sugar, whereas RNA nucleotides contain ribose sugar. This is a key distinguishing feature.
2. Examine the nitrogenous bases present: DNA contains thymine, while RNA contains uracil. This difference in bases is another way to differentiate between the two types of nucleotides.
3. Consider the stability of the nucleotides: DNA is generally more stable than RNA due to the absence of a hydroxyl group at the 2' position of the sugar, which is present in RNA.
4. Analyze the structure of the nucleic acids: DNA is typically double-stranded, forming a double helix, while RNA is usually single-stranded, although it can form complex secondary structures.
5. Review the biological roles: DNA serves as the genetic blueprint in cells, while RNA plays various roles, including acting as a messenger (mRNA), a structural component (rRNA), and a catalyst (ribozymes).