Exocytosis Pathway in Goblet Cells Steps:

• Proteins for mucus are synthesized in the rough ER and transported to the Golgi apparatus.
• In the Golgi, carbohydrates are added to proteins via glycosylation (event 1).
• Modified proteins are packaged into secretory vesicles that separate or bud from the Golgi (event 3).
• Vesicles migrate to the apical plasma membrane and fuse with it (event 2), releasing mucus.

Why B is correct:

• Exocytosis follows the secretory pathway where glycosylation occurs in the Golgi (1), followed by vesicle budding from the Golgi (3), then fusion at the plasma membrane (2), as defined in cell biology.

Why the others are wrong:

• A: Places fusion (2) before vesicle separation (3), but vesicles must form and detach from Golgi before fusing elsewhere.
• C: Includes undefined event 4 and reverses separation (3) after fusion (2), violating vesicle transport order.
• D: Includes undefined event 4 and omits separation (3), ignoring essential vesicle formation step.

Final answer: B