Which molecule carries genetic information from DNA to ribosomes to guide protein synthesis?

• A. DNA
• B. mRNA
• C. tRNA
• D. rRNA

Answer: (B)

Messenger RNA carries the genetic instructions from DNA to the ribosome, where those instructions are used to build proteins. It’s made by transcribing a gene from DNA and then serves as the template for translation at the ribosome. Each three-nucleotide codon on mRNA tells the ribosome which amino acid to add next, with transfer RNA delivering that amino acid in response to the codon. The ribosome moves along the mRNA, reading the sequence and linking amino acids to form the protein.

DNA holds the genetic code and stays largely in the nucleus; it isn’t the direct template used at the ribosome. Transfer RNA is the adapter that brings specific amino acids to the ribosome and recognizes codons, not the message itself. Ribosomal RNA is a structural and catalytic component of the ribosome, helping to make protein but not conveying the genetic instructions.