Unit 3

Which statement best describes diffusion?

• The movement of molecules from an area of low concentration to high concentration.

• The movement of molecules through a membrane using energy.

• The movement of molecules from an area of high concentration to low concentration.

• The movement of water across a membrane from high to low concentration.

Which of the following would increase the rate of diffusion?

• Decreasing the concentration gradient

• Increasing the temperature

• Decreasing the surface area available for diffusion

• I have no idea!

Which of the following best explains why smaller cells are more efficient?

• They have a greater surface area to volume ratio.

• They have a smaller surface area to volume ratio.

• The rate of diffusion is slower in smaller cells.

• Larger cells allow more materials to diffuse in and out quickly.

What happens to a red blood cell placed in a hypotonic solution?

• It shrinks.

• It remains the same size.

• It swells and bursts.

• It gets sad

Why do plant cells not burst when placed in a hypotonic solution?

• They actively pump water out.

• Their cell walls provide structural support.

• Their plasma membranes dissolve in water.

• Because they are awesome

Which of the following is an example of a hypertonic solution?

• A freshwater lake compared to a fish’s body

• Distilled water compared to a cell

• Saltwater compared to a plant cell

• A cup of salt

What determines the direction of water movement in osmosis?

• The molecular size of the solutes.

• The difference in solute concentration between two areas.

• The ATP energy available in the cell.

• The gravity

Which statement best describes a hypotonic solution?

• It has more solutes than the inside of the cell.

• It has fewer solutes and more water than the inside of the cell.

• It has the same solute concentration as the inside of the cell.

• It prevents water from entering or leaving the cell.

Why does the smell of perfume spread across a room?

• The perfume molecules move from high concentration to low concentration.

• The air molecules push the perfume across the room.

• The perfume is actively transported through the air.

• Cold causes the perfume to disappear into the air.

Your friend forgot to drain the pasta water, and now the noodles look swollen. Why?

• The pasta got emotional and absorbed too much water.

• Water moved into the pasta by osmosis because the inside was hypertonic

• The pasta was trying to gain superpowers.

• The starch in the pasta created a magic forcefield.