Which molecule is typically single-stranded?

Which molecule is typically single-stranded?

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

Answer: (C)

RNA is typically single-stranded, which lets it fold into diverse shapes and interact with proteins and other molecules to carry out its many roles in the cell, including mRNA coding, catalysis, and regulation. DNA, on the other hand, is normally double-stranded, forming a stable double helix through complementary base pairing that protects genetic information and enables accurate replication. There are exceptions—RNA can be double-stranded in some viruses or when two RNA strands pair, and DNA can be single-stranded in certain contexts—but the usual state you’re asked to recognize is that RNA is typically single-stranded.

RNA is typically single-stranded, which lets it fold into diverse shapes and interact with proteins and other molecules to carry out its many roles in the cell, including mRNA coding, catalysis, and regulation. DNA, on the other hand, is normally double-stranded, forming a stable double helix through complementary base pairing that protects genetic information and enables accurate replication. There are exceptions—RNA can be double-stranded in some viruses or when two RNA strands pair, and DNA can be single-stranded in certain contexts—but the usual state you’re asked to recognize is that RNA is typically single-stranded.