Question

Identify the polar, inorganic molecule which can pass freely through the plasma membrane.

A. CH₃CH₂OH (ethanol)

B. C₆H₁₂O₆ (glucose)

C. H₂O (water)

D. C₆H₆ (benzene)

E. CO₂ (carbon dioxide)

A plant cell placed into a hypotonic solution will experience which of the following effects?

A. plasmolysis

B. hemolysis

C. shrinkage

D. crenation

E. turgidity

Answer 1

1. Correct answer: C H₂O. Water (H₂O) is uncharged, polar inorganic molecule that can diffuse through the membranes. Ethanol is polar organic molecule and benzene is non-polar molecule. Small non-polar molecules like CO₂ can readily croo the membrane. Larger uncherged polar molecule like glucose cannot pass through the membrane.

2. Correct answer: E. Turgidity. When a plant cell is placed in hypotonic solution it takes up water by osmosis and starts to swell. But the cell wall prevents it from brusting. The plant cell is said to have become turgid.