Question

1. the model shows a substance crossing a cell membrane

solute particle cell membrane
which of the following describes the process?
a. the model shows the process of active transport because the solute particles
are moving from an area of low concentration to an area of high
concentration.
b. the model shows the process of bulk transport because the solute particles
are moving from an area of low concentration to an area of high
concentration.
c. the model shows the process of diffusion because solute particles are
moving from an area of high concentration to an area of low concentration.
d. the model shows the process of osmosis because the solute particles are
moving from an area of high concentration to an area of low concentration.

1. a cell is placed in an isotonic solution. how does the cell maintain homeostasis in

this environment?
a. there is no movement of water molecules into or out of the cell because the
concentrations of solute particles inside and outside the cell are the same.
b. water will move across the cell membrane to the inside of the cell because
the cell has a higher concentration of solute particles than the solution.
c. water will move across the cell membrane to the outside of the cell because
the solution has a higher concentration of solute particles than the cell.
d. water will move across the cell membrane in both directions because the
concentrations of solute particles inside and outside the cell are the same.

Explanation:

Question 11

• Option a: Active transport requires energy and moves from low to high concentration, but the model likely shows diffusion (high to low), so a is wrong.
• Option b: Bulk transport is for large molecules/particles (e.g., endocytosis/exocytosis), not solute particle movement as described, so b is wrong.
• Option c: Diffusion is the passive movement of solutes from high to low concentration, which matches the model's description (solute moving high to low), so c is correct.
• Option d: Osmosis is the movement of water (solvent) across a membrane, not solute particles, so d is wrong.

• In an isotonic solution, solute concentrations inside and outside the cell are equal.
• Option a: Water molecules do move (dynamic equilibrium), so a is wrong.
• Option b: In isotonic, solute concentrations are equal, so water doesn't move to the inside (no higher solute in cell), b is wrong.
• Option c: In isotonic, solute concentrations are equal, so water doesn't move to the outside (no higher solute in solution), c is wrong.
• Option d: In isotonic, water moves in both directions at equal rates (dynamic equilibrium) because solute concentrations are equal, maintaining homeostasis, so d is correct.

Answer:

c. The model shows the process of diffusion because solute particles are moving from an area of high concentration to an area of low concentration.

Question 12