A(n) _ _ solution has the same concentration of water as the cell placed in the solution.
A.
Hypotonic
B.
Isotonic
C.
Diffusive
D.
Osmotic
E.
Hypertonic
The Correct Answer and Explanation is:
The correct answer is B. Isotonic.
Explanation
An isotonic solution is one in which the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. This means that there is no net movement of water into or out of the cell, maintaining cell size and shape. The concept of tonicity—how a solution influences cell volume—is crucial in biology, particularly in understanding cellular behavior in various environments.
When a cell is placed in an isotonic solution, the osmotic pressure is balanced, and the cell remains stable. Water molecules move in and out of the cell at an equal rate, resulting in no net change in the cell’s volume. This is vital for maintaining homeostasis, which is the ability of a cell to regulate its internal environment to maintain stable, constant conditions.
In contrast, if a cell is placed in a hypotonic solution (Option A), the concentration of solutes outside the cell is lower than that inside the cell. This results in water moving into the cell, causing it to swell and potentially burst (lysis). Conversely, in a hypertonic solution (Option E), the concentration of solutes outside the cell is higher, leading to water leaving the cell, which can cause it to shrink (crenation).
The terms “diffusive” (Option C) and “osmotic” (Option D) describe processes rather than types of solutions. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, while osmosis specifically refers to the movement of water across a semipermeable membrane due to concentration differences.
In summary, an isotonic solution is essential for cells to function properly, preventing damage that can occur from excessive swelling or shrinkage caused by differences in solute concentrations.