Cell Structure and Function

What is the function of contractile vacuoles in Amoeba?

• Photosynthesis
• Energy production
• Nutrient storage
• Osmoregulation and excretion

How does the tonoplast affect ion concentration in the vacuole?

• It prevents ion entry
• It allows free diffusion of ions
• It neutralizes ions
• It transports ions against gradients

What percentage of a plant cell's volume can be occupied by the vacuole?

• Up to 20%
• Up to 50%
• Up to 70%
• Up to 90%

What surrounds the vacuole in a cell?

• Plasma membrane
• Double membrane
• Cell wall
• Tonoplast

At what pH are lysosomal enzymes most active?

• Basic pH
• Neutral pH
• Variable pH depending on substrate
• Acidic pH