If a cell is placed in salt water, water leaves the cell by which process?

• A. Facilitated diffusion
• B. Osmosis
• C. Active transport
• D. Endocytosis

Answer: (B)

Verified step by step guidance

1. Understand the concept of osmosis: Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration, aiming to balance solute concentrations on both sides of the membrane.
2. Analyze the scenario: The cell is placed in salt water, which has a higher solute concentration (salt) compared to the inside of the cell. This creates a concentration gradient for water.
3. Determine the direction of water movement: Water will move out of the cell to the salt water because osmosis drives water from areas of lower solute concentration (inside the cell) to areas of higher solute concentration (outside the cell).
4. Eliminate incorrect options: Facilitated diffusion involves the movement of molecules other than water through protein channels, active transport requires energy to move substances against their concentration gradient, and endocytosis involves the cell engulfing materials, none of which describe the movement of water in this case.
5. Conclude the correct process: The movement of water out of the cell in this scenario is best explained by osmosis.