Question

question 4
multiple choice:
the structure of rna differs from dna in that
a rna contains purines but not pyrimidines
b rna contains pyrimidines but not purines
c the backbone of rna contains ribose
d dna contains purines but not pyrimidines
e dna contains pyrimidines but not purines

Explanation:

• Option A: Both RNA and DNA contain purines (adenine and guanine) and pyrimidines. So, this option is incorrect.
• Option B: Both RNA and DNA contain purines (adenine and guanine) and pyrimidines. So, this option is incorrect.
• Option C: The sugar in the backbone of RNA is ribose, while in DNA it is deoxyribose. This is a key structural difference.
• Option D: Both DNA and RNA contain purines (adenine and guanine) and pyrimidines. So, this option is incorrect.
• Option E: Both DNA and RNA contain purines (adenine and guanine) and pyrimidines. So, this option is incorrect.

Answer:

C. the backbone of RNA contains ribose