Unit 3: Cell Transport

What type of molecule diffuses across a selectively permeable membrane during the process of osmosis?

• Carbon dioxide

• Glucose

• Oxygen

• Water

What will be the most likely effect of placing a freshwater protozoan in a highly concentrated saltwater solution?

• The protozoan will burst.

• The protozoan will swell.

• The protozoan will shrink.

• The protozoan will be unaffected.

Tags

NGSS.HS-LS1-3

Which statement about active transport is most accurate?

• Active transport utilizes energy from ATP molecules.

• Active transport is essential to move water into and out of a cell.

• Active transport is the only way to move ions into and out of a cell.

• Active transport is required to move ions into and out of a cell.

Cells use a variety of methods to move essential materials across biological membranes. What process helps to move the molecules shown in the diagram across the membrane?

• Active transport

• Facilitated diffusion

• Osmosis

• Simple diffusion

A cell has a 95% concentration of water inside its membrane. It is placed in an environmental solution that has an 85% concentration of water. In which direction and by what process will water molecules move across the cell membrane?

• Water will move out of the cell, along the concentration gradient, by osmosis.

• Water will move into the cell, along the concentration gradient, by osmosis.

• Water will move out of the cell, against the concentration gradient, by osmosis.

• Water will move into the cell, against the concentration gradient, by osmosis.

A student creates a model to show how red blood cells react when placed in solutions with differing solute concentrations. Based on the size of the arrows, into what type of solution is each red blood cell placed?

• X: hypertonic; Y: isotonic; Z: hypotonic

• X: hypotonic; Y: hypertonic; Z: isotonic

• X: isotonic; Y: hypertonic; Z: hypotonic

• X: isotonic; Y: hypotonic; Z: hypertonic

Tags

NGSS.HS-LS1-3

The diagram shows two types of blood cells, normal blood cells and blood cells after they have been placed in an unknown solution. Into what type of solution were the cells placed?

• Hypotonic

• Hypertonic

• Isotonic

• Osmotic

Under what conditions are solute molecules transported across the cell membrane from the inside to the outside of an animal cell without the utilization of energy?

• when the solute produced by the cell is required for essential functions

• when the solute produced by the cell is a component of the cell membrane

• when the concentration of solute is higher inside the cell than outside the cell

• when the concentration of solute is higher outside the cell than inside the cell

A student places a cell with an initial 5% salt concentration into a solution with a 50% salt concentration. What is most likely to happen and why?

• Water will move out of the cell because there is more salt outside the cell than inside

• Water will move out of the cell because there is more water inside the cell than outside.

• Water will enter the cell because there is more water inside the cell than outside.

• Water will enter the cell because there is more water outside the cell than inside.

Tags

NGSS.HS-LS1-3

In which situation would water enter a cell through osmosis?

• The cell is 20% water, and the cell's environment is 80% water.

• The cell is 50% water, and the cell's environment is 50% water.

• The cell is 60% water, and the cell's environment is 40% water.

• The cell is 80% water, and the cell's environment is 20% water.