Question

The data in the graph are the result of a paramecium being placed in a hypertonic salt solution.

A graph entitled Paramecium Contractile Vacuole Contractions has salt concentration on the horizontal axis and contractions per minute on the vertical axis. A very low salt concentration has 30 contractions per minute, low: 22, medium: 15, high: 8, very-high: 2.

Based on the data in the graph, which would most likely happen if the paramecium were placed in distilled water?
The contractions would increase.
The contractions would decrease.
The contractions would cease altogether.
The contractions would establish dynamic equilibrium.

Answer 1

The contractions would increase.

Explanation: Distilled water is very hypotonic relative to the paramecium, so more water enters by osmosis. The contractile vacuole must pump out the extra water more frequently, raising contractions per minute (as shown by higher rates at lower salt concentrations).