Biology - Grade 10
March 2025
Practice Questions
Cells, Diffusion, Osmosis, Photosynthesis (Plant Nutrition), Leaf Structure and Adaptations for
Photosynthesis
Cells
1. What sort of cells are surrounded by a cell membrane?
2. What are plant cell walls made of?
3. What does fully permeable mean?
4. What does selectively permeable mean?
5. What is the main constituent of cytoplasm?
6. What is vacuole?
7. What is cell sap?
8. Chloroplasts contain chlorophyll. What does chlorophyll do?
9. What happens inside mitochondria?
10. Where are proteins made?
11. What is stored in the nucleus?
12. Why can chromosomes only be seen with a light microscope when a cell is dividing?
Diffusion and Osmosis
13. What is the difference between osmosis and diffusion?
14. List three examples of diffusion and two examples of osmosis occurring in living things.
15. What is meant by a selectively permeable membrane?
16. An animal cell placed in water will burst. Explain fully why a plant cell will not burst when
placed in water.
17. What is meant by flaccid and turgid?
18. What does the terms hypotonic, hypertonic and isotonic solutions mean?
19. How would you describe a solution which has a high concentration of water molecules?
20. What effect does temperature have on the movement of particles?
21. What is plasmolysis?
Photosynthesis
22. Define the terms autotroph and heterotroph.
23. Why must autotrophic nutrition occur before heterotrophic nutrition?
24. Which inorganic substances does a plant use to make food?
25. What kind of energy does a plant use to make carbon dioxide combine with water?
26. What is chlorophyll?
27. What happens when sunlight falls on a chlorophyll molecule?
28. What does a balanced equation show?
29. Write the balanced equation for photosynthesis.
30. Explain what happens in the light and dark stages of photosynthesis
31. State five uses of glucose after it is made by photosynthesis.
32. Name four factors which may limit the rate of photosynthesis of a healthy plant.
33. Why is glucose not very good for storing in a leaf?
Leaf
34. What is another name for a leaf stalk?
35. Which kind of cells make the cuticle on a leaf?
36. What is the function of the cuticle?
37. List three kind of cells in a leaf which contain chloroplasts, and one kind which does not.
38. How does carbon dioxide get into a leaf?
39. How does a leaf obtain its water?
40. State four adaptations of the leaf for photosynthesis.
41. Why are leaves thin?
42. What are stomata?
43. Which part of the leaf are stomata located?
44. Which cells control the opening and closing of the stomatal pore?
45. Why do you think that the stomata of some desert plants close during the day?
46. What are the layers found in the transverse section of a leaf?