| True/False Indicate whether the sentence or statement is true or false. |
| 1. | Diffusion is an active process that requires a cell to expend a great deal of energy. |
| 2. | During diffusion, molecules diffuse from a region where their concentration is low to a region where their concentration is higher until they are evenly dispersed. |
| 3. | A cell placed in a strong salt solution would probably burst because of an increase in osmotic pressure. |
| 4. | When the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell, the cell solution is isotonic relative to its environment. |
| 5. | Diffusion occurs only in living systems. |
| 6. | The transport of specific particles through a membrane by carrier proteins is known as facilitated diffusion. |
| 7. | Ion channels are usually able to transport only one type of ion. |
| 8. | Facilitated diffusion moves molecules and ions in one direction only, while active transport moves them in two directions. |
| 9. | In active transport, energy is required to move a substance across a cell membrane. |
| 10. | Both the sodium-potassium pump and the proton pump require energy to move particles across the cell membrane. |
| 11. | The sodium-potassium pump moves sodium and potassium ions against the concentration gradient. |
| 12. | Exocytosis helps the cell rid itself of wastes. |
| 13. | During the process of exocytosis, the cell membrane extends to engulf substances that are too big to pass through the cell membrane. |
| Completion Complete each sentence or statement. |
| 14. | Active transport systems are a form of cell transport that requires energy from molecules of ____________________. |
| 15. | ____________________ allows a cell to stockpile substances in far greater concentrations than they occur outside the cell. |
| 16. | The transport of food into cells involves the action of the sodium-potassium pump and ____________________ channels. |
| | A B |
| 17. | Refer to the illustration above. The process shown in figure “B” is called ____________________. |
| 18. | Refer to the illustration above. Cells often trap extracellular particles and fluid. This is shown in figure ____________________. |
| 19. | The process in which an amoeba engulfs its prey and takes it in is known as ____________________. |
