RNA that contains instructions for making proteins on ribosomes is called what?

• A. Messenger RNA
• B. Ribosomal RNA
• C. Transfer RNA
• D. Small nuclear RNA

Answer: (B)

Messenger RNA carries the genetic instructions from DNA to the ribosome, where those instructions are read in codons to assemble a protein. It is transcribed from DNA and travels to the ribosome to specify the sequence of amino acids in a growing polypeptide. This sets it apart from ribosomal RNA, which is part of the ribosome's structure and helps catalyze the process; transfer RNA, which brings specific amino acids to the ribosome; and small nuclear RNA, which participates in RNA processing in the nucleus. So the RNA that contains the instructions for making proteins on ribosomes is messenger RNA.