Which of the following is a difference between $\mathrm{RNA}$ and $\mathrm{DNA}$?

• A. $\mathrm{RNA}$ contains uracil, while $\mathrm{DNA}$ contains thymine.
• B. $\mathrm{RNA}$ is double-stranded, while $\mathrm{DNA}$ is single-stranded.
• C. $\mathrm{RNA}$ is more stable than $\mathrm{DNA}$ under alkaline conditions.
• D. $\mathrm{RNA}$ has a deoxyribose sugar, while $\mathrm{DNA}$ has a ribose sugar.

Answer: (A)

Verified step by step guidance

1. Identify the structural components of RNA and DNA. RNA contains the sugar ribose, while DNA contains the sugar deoxyribose. This is a key difference in their structures.
2. Examine the nitrogenous bases present in RNA and DNA. RNA contains the base uracil, whereas DNA contains thymine. This is another fundamental difference between the two nucleic acids.
3. Consider the strand structure of RNA and DNA. RNA is typically single-stranded, while DNA is double-stranded, forming the well-known double helix.
4. Evaluate the stability of RNA and DNA under different conditions. RNA is generally less stable than DNA, especially under alkaline conditions, due to the presence of the 2'-hydroxyl group in ribose.
5. Summarize the differences: RNA contains ribose and uracil and is usually single-stranded, while DNA contains deoxyribose and thymine and is double-stranded. These differences are crucial for their respective biological functions.