Endocytosis and exocytosis Knowledge-Based Download PDF

Questions

1. 1.

   Which of the following characteristics is shared by both endocytosis and exocytosis?

   • A) They transport small nonpolar molecules directly across the hydrophobic interior of the phospholipid bilayer.
   • B) They require cellular energy in the form of ATP to remodel the plasma membrane and transport bulk substances.
   • C) They consistently decrease the total surface area and lipid content of the plasma membrane.
   • D) They depend exclusively on transmembrane channel proteins to move dissolved solutes down their electrochemical gradients.
2. 2.

   Which form of bulk endocytosis allows specialized cells, such as human macrophages, to engulf large solid particles or whole microorganisms through the extension of pseudopodia?

   • A) Pinocytosis
   • B) Receptor-mediated endocytosis
   • C) Exocytosis
   • D) Phagocytosis
3. 3.

   Which of the following transport mechanisms enables a cell to selectively internalize specific extracellular molecules by concentrating them in clathrin-coated pits?

   • A) Phagocytosis
   • B) Pinocytosis
   • C) Receptor-mediated endocytosis
   • D) Exocytosis
4. 4.

   Which of the following cellular processes is responsible for the non-specific internalization of extracellular fluid and dissolved solutes via small vesicles?

   • A) Phagocytosis, which engulfs large solid particles using pseudopodia
   • B) Receptor-mediated endocytosis, which concentrates specific target molecules bound to membrane proteins
   • C) Pinocytosis, which continuously samples extracellular fluid and dissolved molecules in small vesicles
   • D) Exocytosis, which fuses intracellular secretory vesicles with the plasma membrane to expel contents
5. 5.

   Which of the following describes a direct cellular consequence of exocytosis on the plasma membrane?

   • A) The total surface area of the plasma membrane decreases as vesicles pinch inward into the cytoplasm.
   • B) The total surface area of the plasma membrane increases as vesicle membranes fuse and incorporate into it.
   • C) Macromolecules are moved directly across the lipid bilayer through passive transport channels.
   • D) Large molecules exit the cell down their concentration gradient without the expenditure of metabolic energy.