Question

what does it mean for an environment to be isotonic? (1 point)
the concentration of solute is greater in the environment than inside the cell.
the concentration of solute is greater inside the cell than in the environment.
the concentration of solute in the environment and the concentration inside the cell are at equilibrium.
the concentration of solute in the environment is different from the concentration inside the cell.

Explanation:

To determine the meaning of an isotonic environment, we recall the definition of isotonicity in the context of cell biology (a subfield of Biology, which is part of Natural Science). An isotonic solution (or environment, in this case) has the same solute concentration as the solution (or cell, here) it is compared to. This means the solute concentrations are in equilibrium.

• The first option describes a hypertonic environment (solute concentration higher outside the cell).
• The second option describes a hypotonic environment (solute concentration higher inside the cell).
• The fourth option is too vague and does not specifically define isotonicity, as isotonicity requires equal concentrations, not just a difference (which could be hypertonic or hypotonic).
• The third option correctly states that the solute concentration in the environment and inside the cell are at equilibrium, which is the definition of an isotonic environment.

Answer:

C. The concentration of solute in the environment and the concentration inside the cell are at equilibrium.