The ability of a solution to change the volume of a cell by osmosis is measured by which of the following?Multiple choice question.Its tonicityIts concentrationIts osmolarity

The ability of a solution to change the volume of a cell by osmosis is measured by its tonicity.

Tonicity is a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a semipermeable cell membrane. It is influenced by the concentration of solutes on both sides of the membrane. If the concentrations are equal, the solution is said to be isotonic. If the concentrations are unequal, the solution can be either hypertonic (higher concentration of solutes) or hypotonic (lower concentration of solutes).

In the context of cell biology, tonicity is usually used to describe the state of a cell in a solution. If a cell is in a hypertonic solution, water will move out of the cell, causing it to shrink. If a cell is in a hypotonic solution, water will move into the cell, causing it to swell. If a cell is in an isotonic solution, there will be no net movement of water, so the cell will stay the same size.

So, while concentration and osmolarity are related to tonicity, they are not the same thing. Tonicity takes into account the permeability of the cell membrane to different solutes, while osmolarity and concentration do not. Therefore, the correct answer to your question is "Its tonicity".