Understanding Cell Tonicity and Water Movement

What is the process called when water moves across a selectively permeable membrane from an area of high water concentration to an area of low water concentration?

• Diffusion

• Osmosis

• Active transport

• Endocytosis

Which term describes a solution that has a higher concentration of solutes compared to the inside of a cell?

• Isotonic

• Hypotonic

• Hypertonic

• Aquatonic

What happens to a cell placed in a hypotonic solution?

• It shrinks

• It stays the same size

• It swells

• It dissolves

Which of the following best describes diffusion?

• Movement of water from low to high concentration

• Movement of solutes from high to low concentration

• Movement of solutes from low to high concentration

• Movement of water through a protein channel

A cell is placed in an isotonic solution. What will happen to the movement of water?

• Water will only move into the cell

• Water will only move out of the cell

• Water will move in and out at equal rates

• Water will not move at all

If a plant cell is placed in a hypertonic solution, what is the most likely effect on the cell?

• The cell will burst

• The cell will become turgid

• The cell will lose water and shrink

• The cell will remain unchanged

Which scenario best demonstrates osmosis maintaining homeostasis in a cell?

• A cell using energy to pump ions out

• Water moving into a cell to balance solute concentration

• Glucose moving into a cell through a protein channel

• Oxygen diffusing out of a cell

A red blood cell is placed in pure water. Predict and explain what will happen to the cell.

• It will shrink because water leaves the cell

• It will swell and possibly burst because water enters the cell

• It will remain the same size because water does not move

• It will divide rapidly

A student observes that after placing a cell in an unknown solution, the cell shrinks. Using your knowledge of tonicity, what can you infer about the solution and the direction of water movement?

• The solution is hypotonic; water moved into the cell

• The solution is hypertonic; water moved out of the cell

• The solution is isotonic; water did not move

• The solution is hypotonic; water moved out of the cell

You are given three solutions: Solution X (cell swells), Solution Y (cell shrinks), and Solution Z (cell stays the same size). Match each solution to its tonicity (hypotonic, hypertonic, isotonic) and justify your reasoning.

• X: Hypertonic, Y: Hypotonic, Z: Isotonic; because water moves out in hypertonic solutions

• X: Hypotonic, Y: Hypertonic, Z: Isotonic; because water moves into the cell in hypotonic solutions, out in hypertonic, and equally in isotonic

• X: Isotonic, Y: Hypotonic, Z: Hypertonic; because isotonic solutions cause swelling

• X: Hypertonic, Y: Isotonic, Z: Hypotonic; because hypertonic solutions cause swelling