CBSE Class 8 · Science
How Nature Works in Harmony
Official NCERT chapter from Curiosity (book code hecu1). ExamMaster notes are original teaching at CBSE Class 8 depth.
This lesson follows the official chapter “How Nature Works in Harmony” in Curiosity. The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.
- CBSE Class 8
- Easy level
- 8 concepts
1Who All Live Together in Nature?
Who lives together: plants, animals, tiny living things, and the non-living bits (air, water, soil, light) in a place you can point to. Together is a place-list, not a slogan of friendship. One pond is enough.
A zoo poster of distant names is not this together.
Figure. In one place, living things fall into three jobs: make food, eat food, or break remains.
How it works
- Point to a placeThis pond, this hedge.
- List living and non-living bits you can nameWho lives together.
- Keep it localOne case.
2Who Eats Whom?
Who eats whom is a food-link: grass → insect → bird, as a chain you were taught. An arrow means “is eaten by” or “eats”, as the lesson drew it. A cycle of many links is a web if that word was used — still stay with links you can name.
A cute animal at the end of every arrow is a cartoon, not a link.
Figure. Who-eats-whom is a chain of named eaters, not a pile of animals.
How it works
- Name a starting maker (green plant) if that is the lessonThe base.
- Name who eats it, then who eats thatThe whom.
- Refuse a link you cannot justifyHonest arrows.
3What Happens to Waste in Nature?
Waste in nature is stuff living things leave; other living things or weather-jobs can break it and reuse bits, as taught. A plastic pile is a human leftover that may not join that reuse on a school calendar.
“Nature has no waste” as a slogan fails a plastic-heap look.
Figure. Waste does not vanish. Decomposers return salts that plants can use again.
How it works
- Name a leftover that can be broken and reused as taughtA leaf-fall story.
- Name a leftover that sitsA plastic, if that was the contrast.
- Keep reuse as a job, not a magic deleteWaste-heading.
4How Does One Change Lead to Another?
One change leads to another: remove a link, a later eater fails; dirty the water, the pond-jobs thin. A chain of changes is the heading — not a single photo. Keep the chain humble: one cause you can name.
A butterfly-effect story with no named first change is a poster.
Figure. One change is enough to start the next. Cutting trees is not a local-only event.
How it works
- Name one changeThis cut, this dirt.
- Name a next job that fails or shiftsThe lead-to.
- Stop at a chain you can argueNot the whole Earth.
5What Are the Benefits of an Ecosystem?
Benefits of an ecosystem are jobs we can name: clean water, food, a living place, soil-hold — as taught. Benefit is a use-column, not a reason to invent a new science. One place, a few jobs.
A money-slogan with no job is a poster.
Figure. An ecosystem is useful because of jobs it keeps doing, not because it looks green.
How it works
- Name the placeThis forest, this wetland — if you can point.
- Name two jobsHold soil, hold water, hold homes…
- Call those benefits in the use-columnNot a brand.
6A definition is a test you can run
Ecosystem / together is a test: a place plus living and non-living bits plus at least one link. If you only say “nature”, you have a heading.
A green postcard is not the test.
Figure. A definition is a test. Living here means it grows, takes or makes food, and responds.
How it works
- Point to a placeThe object.
- Name a living bit, a non-living bit, and a linkThe test.
- Then the word has contentThe definition ran.
7Name the given before the unknown
The given is the place or the chain asked. The unknown is who-eats-whom or a next change. Copy the local list before you jump to a rainforest you cannot point to.
A documentary still is not your pond.
Figure. Write the given eater pair first. Only then ask what is missing.
How it works
- Name the pointed place or the taught chainThe given.
- Name the next eater or the next changeThe unknown.
- Stay localGiven first.
8One worked case is enough at this class
One pond-chain is enough. A page of the same grass-insect-bird clone does not add a new waste-job.
Ten twins of one arrow are still one idea.
Figure. One fully named chain is enough at this class. A second invented chain does not make the idea stronger.
How it works
- Run one together-list or one eat-linkThe case.
- A second only as a checkOptional.
- StopThis class.
A food-link arrow should be
- A whom you can name — not a cute cartoon
- Any pretty animal
- A lens
Honest arrows.
Notes
- Mapped to the official NCERT chapter “How Nature Works in Harmony”. Original teaching only — no textbook sentences.
- Science here is Physics, Chemistry and Biology ideas at this class, never a language or social-science chapter.
Recap
Hold these pegs from the official chapter “How Nature Works in Harmony”. The wording is ExamMaster’s teaching, not a textbook recap.
- Who All Live Together in Nature?
- Who lives together: plants, animals, tiny living things, and the non-living bits (air, water, soil, light) in a place you can point to.
- Who Eats Whom?
- Who eats whom is a food-link: grass → insect → bird, as a chain you were taught.
- What Happens to Waste in Nature?
- Waste in nature is stuff living things leave; other living things or weather-jobs can break it and reuse bits, as taught.
- How Does One Change Lead to Another?
- One change leads to another: remove a link, a later eater fails; dirty the water, the pond-jobs thin.
- What Are the Benefits of an Ecosystem?
- Benefits of an ecosystem are jobs we can name: clean water, food, a living place, soil-hold — as taught.
- A definition is a test you can run
- Ecosystem / together is a test: a place plus living and non-living bits plus at least one link.
Practise How Nature Works in Harmony
Reading is free and needs no account. Practice, mocks and progress live in the app.
- A 4-question practice set that ends the chapter
- 1 quick check with worked explanations
- Timed mocks scored with the real marking scheme
- Readiness tracked per topic, kept on your device