Worksheet Chapter 2: Ecosystem

1. Explain TWO key reasons why energy decreases continuously as it moves up successive trophic levels in a food pyramid.

2. Which pair of organisms demonstrates a mutualistic relationship?

3. Define the terms (a) Population and (b) Community in an ecosystem context.

4. A simple food chain is given as: Grass → Grasshopper → Frog → Snake. (a) Identify the primary consumer. (b) Explain what happens to the frog population if a disease wipes out all grasshoppers.

5. An oil palm planter suffers major crop losses due to rat infestation. (a) Suggest a biological control method to solve this problem. (b) State TWO advantages of this method over chemical rat poisons.

6. True or False: In a food chain, approximately 90% of energy is passed to the next trophic level.

7. Fill in the blank: The process where plants release water vapor through stomata into the atmosphere is called ________.

8. State TWO biological processes that release carbon dioxide into the atmosphere and ONE process that removes it.

9. Uncontrolled deforestation is occurring in a tropical rainforest. Analyze FOUR negative environmental impacts this activity has on local ecosystems and global nutrient cycles.

10. True or False: Biological control uses natural predators or parasites to regulate pest numbers without synthetic chemicals.