Question

What is the process that involves fusion of a secretory ___ with the plasma membrane and the release of the secretory product across the membranes.

1) Exocytosis
2) Endocytosis
3) Phagocytosis
4) Pinocytosis

Answer 1

Exocytosis is the process where cells expel waste or secrete substances by merging a secretory vesicle with the plasma membrane and releasing the contents outside the cell.

Step-by-step explanation:

The process that involves the fusion of a secretory vesicle with the plasma membrane and the release of the secretory product across the membrane is called exocytosis. This biological mechanism allows cells to expel waste and to secrete substances such as proteins and hormones. During exocytosis, vesicles containing these substances move toward the plasma membrane, merge with it, and release their contents into the extracellular space. The vesicle membrane then becomes a part of the plasma membrane. This process is vital for cells like those in the stomach and pancreas, which secrete digestive enzymes, as well as immune cells that release histamine during an immune response.