Which molecule is single-stranded?

Which molecule is single-stranded?

• A. DNA
• B. RNA
• C. Both DNA and RNA
• D. Neither

Answer: (B)

The main idea here is how nucleic acids are arranged in their usual forms. DNA is typically double-stranded, pairing its two long chains into a stable double helix. RNA, in contrast, is usually a single strand that can fold into complex shapes by internal base pairing, but it does not settle into a fixed two-strand helix like DNA. Because of this, RNA is the single-stranded molecule in the common biological scenario. There are exceptions in biology, but for the standard understanding, RNA is single-stranded.

The main idea here is how nucleic acids are arranged in their usual forms. DNA is typically double-stranded, pairing its two long chains into a stable double helix. RNA, in contrast, is usually a single strand that can fold into complex shapes by internal base pairing, but it does not settle into a fixed two-strand helix like DNA. Because of this, RNA is the single-stranded molecule in the common biological scenario. There are exceptions in biology, but for the standard understanding, RNA is single-stranded.