Final answer:
O-linked glycosylation typically takes place in the Golgi apparatus, where additional sugars are appended to the oligosaccharides that began their synthesis in the rough endoplasmic reticulum.
Step-by-step explanation:
O-linked glycosylation can occur in the Golgi apparatus. The process of oligosaccharide synthesis begins in the rough endoplasmic reticulum (RER) with the generation of a core glycoside. Proteins then travel through the endomembrane system, undergoing further glycosylation in the Golgi apparatus, where more sugars are added. This completes the synthesis of glycoproteins. Such post-translational modifications are significant because they often play a crucial role in the function, destination, and recognition of proteins, especially those in the cell membrane and those that are secreted out of the cell.