Name__________________________________________Date__________________Class__________ Homeostasis and Transport Worksheet Answer questions on YOUR paper and then staple this sheet onto it. 1. What limits the size of cells? (p 70) 2. Why do cells have different shapes? (71) 3. Define: selectively permeable (73) 4. Draw and label figure 4.5 on p 74 and describe the function of each structure. 5. What is the fluid mosaic model? (75) 6. Define diffusion and equilibrium, and explain how equilibrium is established as a result of diffusion. P95 7. What is the difference between diffusion and osmosis? 95-96 8. How do substances cross the cell membrane through facilitated diffusion? 99 9. Define: hypertonic, hypotonic, and isotonic. 96-7 10. Which way will water move if a cell is in (a) a hypotonic (b) hypertonic and (c) isotonic solution? 97 11. How do unicellular organisms like paramecium rid themselves of excess water?97 12. Describe the type of environment you find plant cells in, and desctibe turgor pressure.98 13. What’s plasmolysis? 98 14. What happens to animal cells placed in (a) a hypotonic (b) hypertonic and (c) isotonic solution? 98 15. Define cytolysis. 99 16. What is an example of a substance that moves across the membrane by facilitated diffusion? 100 17. Define ion channels. 100 18. Compare active and passive transport.95, 101 19. Describe the functioning of the sodium-potassium pump. (fig 5.4, p 102) 20. What is endocytosis? Describe the two types. 103 21. What are phagocytes? 104 22. What’s exocytosis? 104 23. Tell whether each of the following is an example of active or passive transport: facilitated diffusion, Osmosis, pumps, exocytosis, endocytosis, pinocytosis, phagocytosis, diffusion.