One of the primary functions of RNA molecules is to:

• A. Catalyze the replication of DNA by unwinding the double helix
• B. Carry genetic information from DNA to ribosomes and help direct protein synthesis
• C. Store hereditary information as the cell’s long-term genetic archive
• D. Form the phospholipid bilayer that makes up the cell membrane

Answer: (B)

Verified step by step guidance

1. Identify the main types of RNA and their functions: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
2. Understand that mRNA carries genetic information from DNA in the nucleus to ribosomes in the cytoplasm, where proteins are synthesized.
3. Recognize that RNA does not store hereditary information long-term; that role belongs to DNA.
4. Note that RNA molecules do not form the phospholipid bilayer; this is a function of lipids in the cell membrane.
5. Conclude that the primary function of RNA is to carry genetic information from DNA to ribosomes and help direct protein synthesis.