Final answer:
mRNA is responsible for copying and carrying the genetic code from DNA to produce proteins through the processes of transcription in the nucleus and translation in the cytoplasm.
Step-by-step explanation:
Messenger RNA, commonly known as mRNA, plays a critical role in the process of gene expression. Its primary function is to copy the genetic code needed to produce proteins from DNA and carry it to the ribosome, which is the cellular machinery responsible for synthesizing proteins. Transcription is the process through which mRNA is synthesized; this occurs in the nucleus of eukaryotic cells or the nucleoid region in prokaryotes. The sequence of bases in mRNA dictates the sequence of amino acids that will be joined together to form a polypeptide chain, ultimately folding into a functional protein.
The genetic information transcribed onto the mRNA molecule is represented by codons—groups of three nucleotides—that correspond to specific amino acids. This happens in a process called translation, which occurs in the cytoplasm. Here, the mRNA interacts with ribosomes and tRNA molecules to assemble the polypeptide chains. The genetic code carried by mRNA ensures that proteins are created accurately as per the instructions encoded in the DNA. Given that proteins are critical for virtually all cellular functions, the accurate copying and transmission of genetic information by mRNA is essential to the life of the cell.