Question

which of the following difference between dna and rna allows them to perform their unique functions?
○ dna contains ribose, while rna contains deoxyribose.
○ dna is single - stranded, whereas rna is double - stranded.
○ dna contains thymine, while rna contains uracil.
○ rna is found only in the nucleus, while dna is found only in the cytoplasm.

Explanation:

• The first option is incorrect: DNA has deoxyribose, RNA has ribose.
• The second option is incorrect: DNA is double-stranded, RNA is mostly single-stranded.
• The fourth option is incorrect: DNA is mainly in the nucleus, RNA is made in the nucleus and functions in the cytoplasm.
• The third option is correct: This nitrogenous base difference, along with structural differences, supports their unique roles (DNA stores genetic info, RNA transfers/expresses it).

Answer:

C. DNA contains thymine, while RNA contains uracil.