What is the major function of ribosomes?

Ribosomes play a crucial role in protein synthesis, a process fundamental to cellular function and biology. They are the cellular machinery that translates messenger RNA (mRNA) sequences into polypeptide chains, which eventually fold into functional proteins. This process begins when mRNA, transcribed from DNA, is transported out of the nucleus into the cytoplasm, where ribosomes are located.

During translation, ribosomes facilitate the coupling of transfer RNA (tRNA) molecules to the mRNA template, ensuring that the correct amino acids are added in the proper sequence. The ribosome reads the codons on the mRNA, each of which encodes a specific amino acid, and facilitates the formation of peptide bonds between adjacent amino acids. This process ultimately leads to the generation of proteins that are essential for various cellular functions, including catalyzing metabolic reactions, providing structural support, and regulating cellular processes.

While options such as the replication of DNA, cell division, and transportation of RNA are essential biological processes, they do not directly involve ribosomes. Thus, protein synthesis stands as the primary function of ribosomes, making it the correct answer in this context.