Lesson 12 of 14
The big picture
Show on a big screenEverything in a place is linked. Change one part, and the other parts change.
| Idea | Remember |
|---|---|
| Living and non-living together | Biotic plus abiotic parts make an ecosystem |
| One kind, or all kinds | A population is one kind. A community is all the populations there |
| Where the food starts | Producers make food. Consumers eat |
| Along the chain | The arrow points from food to eater |
| Chains join into a web | Many eaters have more than one food |
| The crew that puts it back | Decomposers return nutrients to the soil |
| Pull one link | Fewer eaters, more food. Less food, fewer eaters |
| People are in the picture | People's changes follow the same links |
| Water, land and farms | Aquatic ecosystems are in water, such as ponds, rivers and lakes. Terrestrial ecosystems are on land, such as forests, grasslands and deserts. Farmland is on land. People made it, so it is human-made. |
| Living together | Mutualism: both partners gain. Commensalism: one gains, and the other is neither helped nor harmed. Parasitism: one lives on or in the other and harms it. |
Open Chapter 12, How Nature Works in Harmony, in your NCERT book. Read it with your teacher.