Water moves into the cell by a process called?

Water moves into the cell by a process called?

• A. Diffusion
• B. Active transport
• C. Osmosis
• D. Filtration

Answer: (C)

Osmosis is the diffusion of water across a selectively permeable membrane. Water moves from where its concentration (and water potential) is higher to where it is lower, effectively from areas of lower solute concentration to higher solute concentration inside the membrane, until the system reaches balance. Because the membrane lets water pass but restricts many solutes, water shifts to equalize solute levels, which is why a cell in a dilute environment gains water and swells (though a plant cell becomes turgid due to the cell wall). This is different from simple diffusion, which describes the spread of any small molecules from high to low concentration and doesn’t specifically involve water crossing a membrane. It’s also distinct from active transport, which requires cellular energy to move substances against their gradient, and from filtration, which is driven by pressure rather than a solute concentration gradient.

Osmosis is the diffusion of water across a selectively permeable membrane. Water moves from where its concentration (and water potential) is higher to where it is lower, effectively from areas of lower solute concentration to higher solute concentration inside the membrane, until the system reaches balance. Because the membrane lets water pass but restricts many solutes, water shifts to equalize solute levels, which is why a cell in a dilute environment gains water and swells (though a plant cell becomes turgid due to the cell wall).

This is different from simple diffusion, which describes the spread of any small molecules from high to low concentration and doesn’t specifically involve water crossing a membrane. It’s also distinct from active transport, which requires cellular energy to move substances against their gradient, and from filtration, which is driven by pressure rather than a solute concentration gradient.