Which pair correctly states two basic differences between DNA and RNA?

• A. RNA and DNA both contain ribose sugar and both use uracil (U).
• B. RNA is always double-stranded and contains thymine (T).
• C. RNA contains ribose sugar and uses uracil (U) instead of thymine (T).
• D. RNA contains deoxyribose sugar and uses thymine (T) instead of uracil (U).

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the basic chemical components of DNA and RNA, focusing on their sugar molecules and nitrogenous bases.
2. Step 2: Recall that DNA contains deoxyribose sugar, while RNA contains ribose sugar. This is a fundamental difference in their sugar backbone.
3. Step 3: Identify the nitrogenous bases present in each molecule. DNA uses thymine (T), whereas RNA uses uracil (U) instead of thymine.
4. Step 4: Evaluate the statements given in the problem by comparing them to these known differences: sugar type and presence of thymine or uracil.
5. Step 5: Conclude which pair correctly states two basic differences by confirming that RNA contains ribose sugar and uses uracil (U) instead of thymine (T).