mRNA is best described as which of the following?

• A. Type of RNA that carries instructions from DNA in the nucleus to the ribosome
• B. Type of RNA that carries amino acids to the ribosome
• C. A type of DNA that codes for proteins
• D. A protein that forms ribosomes

Answer: (A)

mRNA serves as the messenger that carries the genetic instructions from DNA in the nucleus to the ribosome, where those instructions are read to assemble proteins. It is transcribed from DNA and provides the codons that specify which amino acids to link together during translation. It does not carry amino acids itself (that’s the job of tRNA), and it is not DNA or a protein—mRNA is a single-stranded RNA molecule.