Question

Microvilli are filamentous structures on the surface of intestinal cells. Their formation depends on microfilaments. What would happen to intestinal cells when microfilaments formation is blocked by cytochalasin, a chemical that inhibits actin polymerization?

A. Surface area decreases: cell volume decreases; efficiency of nutrient uptake increases.
B. Surface area does not change: cell volume decreases: efficiency of nutrient uptake increases.
C. Surface area decreases: cell volume decreases; efficiency of nutrient uptake does not change.
D.Surface area decreases, cell volume does not change; efficiency of nutrient uptake decreases.

Answer 1

Blocking microfilaments with cytochalasin prevents microvilli formation, leading to a decrease in surface area and a subsequent decrease in the efficiency of nutrient uptake in intestinal cells, while cell volume remains unchanged. The correct option is D.Surface area decreases, cell volume does not change; efficiency of nutrient uptake decreases.

Step-by-step explanation:

When the formation of microvilli is blocked by cytochalasin, a chemical that inhibits actin polymerization, the following would happen to intestinal cells:

• Surface area decreases: Microvilli are projections on the surface of intestinal cells that increase the surface area for absorption. Without actin polymerization, microvilli cannot form properly.
• Cell volume does not change: The prevention of microvilli formation does not directly affect the overall volume of the cell.
• The efficiency of nutrient uptake decreases: The surface area available for the absorption of nutrients is greatly reduced without the presence of microvilli, therefore lowering the efficiency of nutrient uptake.

The correct answer, in this case, is D: Surface area decreases, cell volume does not change; efficiency of nutrient uptake decreases. The correct option is D.Surface area decreases, cell volume does not change; efficiency of nutrient uptake decreases.