Question

which of the following structures helps regulate osmotic pressure in protozoan cells?

• contractile vacuole
• mitochondrion
• peroxisome
• nucleus

Explanation:

The contractile vacuole in protozoan cells collects and expels excess water, thereby regulating osmotic pressure. Mitochondria are for energy - production, ribosomes for protein - synthesis, and lysosomes for digestion.

Answer:

Contractile vacuole