Diffusion and Osmosis

Which definition of diffusion is correct?

• the movement of molecules from a higher to a lower concentration, against a concentration gradient

• the movement of molecules from a higher to a lower concentration, down a concentration gradient

• the movement of molecules from a lower to a higher concentration, against a concentration gradient

• the movement of molecules from a lower to a higher concentration, down a concentration gradient

Visking tubing is a partially permeable membrane.

Some Visking tubing containing a concentrated sugar solution is weighed and placed in distilled water, as shown.

After two hours the Visking tubing is removed and re-weighed.

What happens to the mass and why?

• It decreases because sugar moves out.

• It decreases because water moves out.

• It increases because sugar moves in.

• It increases because water moves in.

Carbon dioxide moves into and out of cells by diffusion.

Which statement is correct for a plant cell that is photosynthesising in bright sunlight?

• Carbon dioxide diffuses into the cell because the concentration of carbon dioxide is higher outside the cell than inside the cell.

• Carbon dioxide diffuses out of the cell because the concentration of carbon dioxide is higher outside the cell than inside the cell.

• Carbon dioxide diffuses into the cell because the concentration of carbon dioxide is lower outside the cell than inside the cell.

• Carbon dioxide diffuses out of the cell because the concentration of carbon dioxide is lower outside the cell than inside the cell

Tags

NGSS.HS-LS2-5

The diagram shows four cells that contain oxygen molecules. The concentration of oxygen in each cell is different. In which direction do the oxygen molecules diffuse?

• A

• B

• C

• D

Tags

NGSS.HS-LS2-3

The diagram represents oxygen molecules around and inside a cell.

Which statement explains why oxygen molecules move into the cell?

• The oxygen molecules move from a high to a low concentration by diffusion.

• The oxygen molecules move from a high to a low concentration by osmosis.

• The oxygen molecules move from a low to a high concentration by diffusion.

• The oxygen molecules move from a low to a high concentration by osmosis.

Tags

NGSS.MS-LS1-2

One beaker contains water. Another beaker contains a concentrated salt solution. A red blood cell is placed into each beaker.

Which diagram shows the appearance of the cells after 15 minutes?

• 
• 
• 
• 

• A

• B

• C

• D

Tags

NGSS.HS-LS1-3

• Sugar has moved into the cell.

• Sugar has moved out of the cell.

• Water has moved into the cell.

• Water has moved out of the cell.

Tags

NGSS.MS-LS1-2

• A

• B

• C

• D

Tags

NGSS.HS-LS1-3

Which is the correct definition of osmosis?

• passage of water molecules from a region of their higher concentration to a region of their lower concentration, through a permeable membrane

• passage of water molecules from a region of their higher concentration to a region of their lower concentration, through a partially permeable membrane

• passage of water molecules from a region of their lower concentration to a region of their higher concentration, through a permeable membrane

• passage of water molecules from a region of their lower concentration to a region of their higher concentration, through a partially permeable membrane