Question

the model below compares the typical structures of rna and dna. all possible rna and dna nucleotides are shown.
rna (strand)
dna (double helix)
nitrogenous bases:

• adenine
• thymine
• guanine
• cytosine
• uracil

(ribose - phosphate backbone)
(deoxyribose - phosphate backbone)
(hydrogen bonds between base pairs)
what are the main differences between rna and dna? select all that apply.
the 5 - carbon sugar in rna is ribose instead of deoxyribose.
rna contains sulfide groups instead of phosphate groups.
rna is usually single - stranded, not double - stranded.
rna uses a nitrogenous base called uracil instead of thymine.

Explanation:

• Option A: RNA's sugar is ribose, DNA's is deoxyribose (missing an -OH group), so this is correct.
• Option B: Both RNA and DNA have phosphate groups in their backbones, so this is incorrect.
• Option C: RNA is typically single - stranded, while DNA is double - stranded (double helix), so this is correct.
• Option D: RNA uses uracil (U) and DNA uses thymine (T) as a nitrogenous base, so this is correct.

Answer:

A. The 5-carbon sugar in RNA is ribose instead of deoxyribose.
C. RNA is usually single - stranded, not double - stranded.
D. RNA has a nitrogenous base called uracil instead of thymine.