In what way are the structures of RNA and DNA similar?

• A. Both contain the sugar deoxyribose.
• B. Both are composed of nucleotides.
• C. Both have a double helix structure.
• D. Both use uracil as a nitrogenous base.

Answer: (B)

Verified step by step guidance

1. Begin by understanding the basic structure of nucleic acids. Both RNA and DNA are composed of long chains of nucleotides, which are the building blocks of these molecules.
2. Each nucleotide consists of three components: a sugar molecule, a phosphate group, and a nitrogenous base. In DNA, the sugar is deoxyribose, while in RNA, the sugar is ribose.
3. Identify the nitrogenous bases present in each type of nucleic acid. DNA contains adenine (A), thymine (T), cytosine (C), and guanine (G). RNA contains adenine (A), uracil (U), cytosine (C), and guanine (G). Note that uracil is used in RNA instead of thymine.
4. Consider the structural differences between RNA and DNA. DNA typically forms a double helix structure, whereas RNA is usually single-stranded and does not form a double helix.
5. Conclude by recognizing the similarity in composition: both RNA and DNA are composed of nucleotides, which is the correct answer to the question about their structural similarity.