๐ Class 8 Science – Curiosity Chapter 12
๐ฟ How Nature Works in Harmony
๐ข 1. Refer to the given diagram (Fig. 12.19) and select the wrong statement.
❌ Answer:
๐ (iii) An ecosystem is part of a community
๐ง Explanation:
๐ Relationship:
Population < Community < Ecosystem ✔️
๐ Conclusion:
- (i) ✔️ Correct
- (ii) ✔️ Correct
- (iii) ❌ Wrong (because ecosystem is larger, not part of community)
๐ข 2. A population is part of a community. If all decomposers suddenly disappear from a forest ecosystem, what changes do you think would occur? Explain why decomposers are essential.
✅ Answer:
๐ง If decomposers disappear:
- ๐ Dead plants and animals will accumulate
- ♻️ Nutrients will not return to soil
- ๐ฑ Soil fertility will decrease
- ๐ Entire ecosystem balance will be disturbed
๐ Importance of Decomposers:
- ๐ Recycle nutrients (เคชोเคทเค เคคเคค्เคต)
- ๐ฑ Maintain soil fertility
- ♻️ Keep natural cycles running
๐ Conclusion: Decomposers are essential for ecosystem balance ✔️
๐ข Class 8 Science Curiosity Chapter 12 Question 3 and 4
๐ข 3. Selvam from Cuddalore district, Tamil Nadu, shared that his village was less affected by the 2004 Tsunami compared to nearby villages due to the presence of mangrove forests. This surprised Sarita, Shabnam, and Shijo. They wondered if mangroves were protecting the village. Can you help them understand this?
✅ Answer:
๐ Yes, mangroves protect coastal areas ✔️
๐ฟ Role of Mangroves:
- ๐ Act as natural barriers
- ๐จ Reduce speed of strong waves & winds
- ๐ฑ Roots hold soil → prevent erosion
๐ข 4. Look at this food chain:
Grass → Grasshopper → Frog → Snake
If frogs disappear from this ecosystem, what will happen to the population of grasshoppers and snakes? Why?
✅ Answer:
๐ข Question 5 and 6 of Class 8 Science Curiosity Chapter 12
๐ข 5. In a school garden, students noticed fewer butterflies the previous season. What could be the possible reasons? What steps can students take to have more butterflies on campus?
✅ Answer:
๐ Possible Reasons:
- ๐ธ Fewer flowering plants (less nectar)
- ☠️ Use of pesticides
- ๐ฆ️ Climate or habitat changes
๐ฑ Steps to Increase Butterflies:
- ๐บ Grow more flowering plants
- ๐ซ Avoid chemical pesticides
- ๐ฟ Maintain natural habitat
๐ข 6. Why is it not possible to have an ecosystem with only producers and no consumers or decomposers?
✅ Answer:
- ๐ฑ Producers
- ๐พ Consumers
- ♻️ Decomposers
๐ For a balanced ecosystem ✔️
๐ข Class 8 Science Curiosity Chapter 12 Question 7 and 8
๐ข 7. Observe two different places near your home or school (e.g., a park and a roadside). List the living and non-living components you see. How are the two ecosystems different?
✅ Answer:
๐ณ Park Ecosystem:
Living:
- ๐ณ Trees, grass
- ๐ฆ Birds, insects
- ๐ฟ️ Squirrels
Non-living:
- ๐ฑ Soil, water
- ☀️ Sunlight
- ๐ฌ️ Air
๐ฃ️ Roadside Ecosystem:
Living:
- ๐ฟ Few plants
- ๐ Stray dogs
- ๐ฆ Crows, ants
Non-living:
- ๐งฑ Concrete
- ๐ซ️ Dust
- ๐ Vehicles, heat
๐ Difference:
- Park → ๐ฟ High biodiversity & balance
- Roadside → ⚠️ Less greenery, more pollution
๐ข 8. ‘Human-made ecosystems like agricultural fields are necessary, but they must be made sustainable.’ Comment on the statement.
✅ Answer:
⚠️ Problems (Unsustainable practices):
- ☠️ Excess pesticides
- ๐พ Monoculture
- ๐ง Overuse of water
๐ฑ Sustainable Solutions:
- ๐ฟ Organic farming
- ๐ Crop rotation
- ๐ง Water conservation
๐ข Class 8 Science Curiosity Chapter 12 Question 9
๐ข 9. If the Indian hare population (Fig. 12.20) drops because of a disease, how would it affect the number of other organisms?
✅ Answer:
