Final answer:
The Golgi body, also known as the Golgi apparatus, is responsible for finishing, packaging, and exporting proteins from the cell.
Step-by-step explanation:
The organelle that finishes a protein and packages it for export is the Golgi body. This organelle, also known as the Golgi apparatus or Golgi complex, is responsible for manipulating products, such as proteins, from the rough Endoplasmic Reticulum (ER). It organizes, modifies, packages, and tags these proteins into membrane-bound vesicles. Some of these vesicles are then transported to other parts of the cell, while others are exported out of the cell through a process known as exocytosis. For enzymatic proteins, they are packaged as new lysosomes or targeted to fuse with existing lysosomes. The Golgi body functions as the cell's 'post office,' where it receives proteins from the rough ER through transport vesicles, processes and sorts them, and then dispatches them to their correct destinations within or outside of the cell.