If DNA is described as a double helix, how should mRNA be described?

• A. Single-stranded
• B. Circular duplex
• C. Triple helix
• D. Double helix

Answer: (A)

Verified step by step guidance

1. Recall the structure of DNA: it is described as a double helix because it consists of two complementary strands twisted around each other.
2. Understand that mRNA (messenger RNA) is synthesized from one strand of DNA during transcription and serves as a template for protein synthesis.
3. Recognize that unlike DNA, mRNA is typically composed of a single strand, not two strands twisted together.
4. Consider the options given: 'Single-stranded', 'Circular duplex', 'Triple helix', and 'Double helix'.
5. Conclude that since mRNA is single-stranded and does not form a double helix like DNA, the correct description is 'Single-stranded'.