Chapter 12 Solutions — How Nature Works in Harmony

Keep the Curiosity Alive

1. 1.
   Refer to the given diagram (Fig. 12.19) and select the wrong statement.

   • (i) A community is larger than a population.
   • (ii) A community is smaller than an ecosystem.
   • (iii) An ecosystem is part of a community.
2. 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.
3. 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?
4. 4.
   Look at this food chain: Sun → Grass → Grasshopper → Frog → Snake If frogs disappear from this ecosystem, what will happen to the population of grasshoppers and snakes? Why?
5. 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?
6. 6.
   Why is it not possible to have an ecosystem with only producers and no consumers or decomposers?
7. 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?
8. 8.
   'Human-made ecosystems like agricultural fields are necessary, but they must be made sustainable.' Comment on the statement.
9. 9.
   If the Indian hare population (Fig. 12.20) drops because of a disease, how would it affect the number of other organisms?