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CBSE Class 10 · Science

Our Environment

Official NCERT chapter from Science (book code jesc1). ExamMaster notes are original teaching at CBSE Class 10 depth.

This lesson follows the official chapter “Our Environment” in Science. 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 10
  • Medium level
  • 8 concepts

1ECO-SYSTEM — WHAT ARE ITS COMPONENTS?

An ecosystem’s components are the living bits and the non-living bits in a place you can point to: plants, animals, tiny living things, plus air, water, soil, light. Component is a who-is-here list, not a slogan of harmony. One pond is enough.

A zoo poster of distant names is not this pond.

Figure. An ecosystem is one working place: living parts (plants, animals, microbes) and non-living parts (air, water, soil, sunlight) in the same box. Pull one column out and the other cannot keep the same jobs.

How it works

  1. Point to a placeThis pond, this hedge.
  2. List living and non-living bitsThe components.
  3. Keep it localOne case.

2FOOD CHAINS AND WEBS

A food chain is a who-eats-whom line; a web is those lines sharing eaters, as taught. An arrow means the lesson’s eat-direction. A cute animal at every tip is a cartoon, not a link.

A brand mascot is not a trophic step.

Figure. A food chain is one eat-path. A food web is two or more chains that share a species — here both paths meet at the snake. Exam diagrams ask you to name a producer, a herbivore, and where the paths join.

How it works

  1. Name a starting makerThe green base, if taught.
  2. Name who eats it, then who eats thatThe chain.
  3. If lines share, call it a webHonest arrows.

3OZONE LAYER AND HOW IT IS GETTING DEPLETED

Ozone high up is a taught shield-job against a named harmful bit of sunlight; depleted means that job thins. A leftover human-made bit the lesson named can thin it. Ozone-here is that high shield, not “the smell after a copier” unless the lesson split those.

A sunscreen advert is not the shield.

Figure. The ozone layer is a thin O3 band that stops most UV before it reaches the air we breathe. A CFC-thinned gap lets one UV path through — that is depletion, not the layer vanishing everywhere.

How it works

  1. Name the high shield-jobOzone as taught.
  2. Name a leftover that thins it, if listedThe deplete.
  3. Keep the claim at that shieldNot every smell.

4MANAGING THE GARBAGE WE PRODUCE

Garbage we produce is leftover we made; managing means a named job: reduce, reuse, recycle, or a taught dump-sort — not “away”. A pile that sits is still here. One bin-sort you can point to is enough.

A truck driving off-camera is not manage.

Figure. Managing garbage is choosing a path. Reduce, reuse, and recycle cut what must be stored. Dumping is the leftover path, not a disappearing act.

How it works

  1. Name the leftoverThis plastic, this peel.
  2. Name a job (sort, reuse, a taught pit)Manage.
  3. Refuse “away” as a placeStill on the map.

5Producers start the food chain

Producers start the food chain: green plants (and the taught makers) that make food. A producer is a make-job, not “the first cute thing in a poster”. No producer, no school chain.

A lion at the start of a chain is a miss unless the lesson had a special case.

Figure. A producer is the green plant that makes food from light. Every later eater in this chain is only rearranging that food. Start the chain at the plant, not at the first animal you notice.

How it works

  1. Name a makerGreen plant — as taught.
  2. Put it at the startThe producer.
  3. Then the first eaterThe chain can begin.

6Energy drops as you go up a trophic level

Energy drops as you go up a trophic level: each step keeps only a school-share (10% if that number was taught) and the rest is leftover heat-and-jobs. Drop is why chains stay short. A longer cartoon chain with no drop is a poster.

Adding energy at each eater “because they look strong” is a miss.

Figure. Lindeman's 10% law: of 10000 J fixed by producers, about 1000 J reach herbivores, 100 J the next carnivores, and 10 J the top. The axis is logarithmic so all four decades stay visible — a linear pyramid would hide the top bar.

How it works

  1. Name two stepsMaker → eater.
  2. Say the next step has less of the energy-shareThe drop.
  3. Keep the chain humbleShort, as taught.

7Biodegradable and non-biodegradable are two tests

Biodegradable leftovers can be broken by living jobs on a school calendar; non-biodegradable ones sit. Two tests, not a vibe of “natural”. A peel can go; a taught plastic often sits.

“Eco” printed on plastic is not the test.

Figure. Biodegradable and non-biodegradable are tests you run on the material, not on the object. A peel and paper are acted on by microbes; a plastic bottle can sit in the same dump and still be plastic.

How it works

  1. Name the leftoverPeel or plastic — as given.
  2. Ask: can living jobs break it here in a school time?The test.
  3. Hang bio or non-bioTwo drawers.

8A miss: treating “away” as a place

A miss: treating “away” as a place. The truck left the street; the leftover still sits in a dump, a river, or the air. Away is a word, not a coordinate. Managing names the next sit.

A clean desk with a full skip downstairs is not gone.

Figure. Throwing something 'away' names no place. The honest path is bin to landfill to soil or water. Away is a word, not a destination — that is the miss this chapter is written to catch.

How it works

  1. Ask where the leftover wentThe next sit.
  2. Name that placeStill on the map.
  3. Call “away” a miss-wordThis heading.
“Thrown away” means
  1. The leftover still sits somewhere — name that sit
  2. It left the Earth
  3. It became a producer

Away is not a place.

Notes

  • Mapped to the official NCERT chapter “Our Environment”. 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 “Our Environment”. The wording is ExamMaster’s teaching, not a textbook recap.

ECO-SYSTEM — WHAT ARE ITS COMPONENTS?
An ecosystem’s components are the living bits and the non-living bits in a place you can point to: plants, animals, tiny living things, plus air, water, soil, light.
FOOD CHAINS AND WEBS
A food chain is a who-eats-whom line; a web is those lines sharing eaters, as taught.
OZONE LAYER AND HOW IT IS GETTING DEPLETED
Ozone high up is a taught shield-job against a named harmful bit of sunlight; depleted means that job thins.
MANAGING THE GARBAGE WE PRODUCE
Garbage we produce is leftover we made; managing means a named job: reduce, reuse, recycle, or a taught dump-sort — not “away”.
Producers start the food chain
Producers start the food chain: green plants (and the taught makers) that make food.
Energy drops as you go up a trophic level
Energy drops as you go up a trophic level: each step keeps only a school-share (10% if that number was taught) and the rest is leftover heat-and-jobs.

Practise Our Environment

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  • 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
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