[Campbell Biology P.183] What is tonicity, and what is its primary determinant regarding sol... | Practice Question

What is tonicity, and what is its primary determinant regarding solutions and cell water balance?

  • A: The rate of solute diffusion, primarily determined by membrane permeability.
  • B: The ability of a surrounding solution to cause a cell to gain or lose water, primarily determined by the concentration of nonpenetrating solutes.
  • C: The overall concentration of all solutes in a solution, determining the cell's turgor pressure.
  • D: The balance of water between a cell and its environment, primarily influenced by the cell wall's rigidity.

Explanation

Tonicity is defined as the ability of a surrounding solution to cause a cell to gain or lose water. This ability is primarily determined by the concentration of nonpenetrating solutes in the solution relative to that inside the cell, as these solutes cannot cross the membrane and thus create an osmotic gradient.