Grade 5 (age 10-11)

Ecosystem

An ecosystem is a web where living things and their surroundings shape each other. Producers make their own food, consumers eat other living things, and decomposers break down the dead. A frog eating a grasshopper that ate grass forms a food chain. Here you build the chain step by step and watch how the ecosystem stays in balance.

What is a Food Chain?

Level4

🌿 Food Chain

①Producer (grass): makes own food (photosynthesis)

②Primary consumer (grasshopper): eats plants (herbivore)

③Secondary consumer (frog): eats primary consumers

④Tertiary consumer (snake): eats secondary consumers

⑤Top consumer (eagle): top of the chain

Ecological Pyramid

Balance50

🔺 Why a Pyramid Shape?

①Most grass, fewest eagles

②Energy decreases moving up the chain!

③100 grass → 20 grasshoppers → 8 frogs → 3 snakes → 1 eagle

④If the bottom disappears, the top cannot survive

Ecosystem Balance

Ecosystem Composition

Ecosystem = Living things (animals, plants, microbes) + Environment (light, water, soil, air)

Living things and environment influence each other

💡 When Ecosystems Are at Risk

①Forest loss → no food and shelter for animals

②River pollution → fewer fish, fewer birds

③Invasive species → push out native species

④We must reduce waste and protect nature!

Summary

Ecosystem Core

Producer -> Primary -> Secondary -> Top consumer

Connected food chains form a food web

🎯 Key Points

①Food chain: eat-and-be-eaten relations linked like a chain

②Producer: plants (make own food)

③Consumer: animals (eat other living things)

④Decomposer: bacteria, fungi (break down dead matter)

⑤Broken balance affects everyone!

Examples and Unit Test

Example 1

In the food chain grass → grasshopper → frog → snake → eagle, which is the producer that makes its own food?

A producer makes its own food by photosynthesis; consumers eat other living things.

Here the grass (a plant) makes its own food, so it is the producer.

▸ The grass (a plant)

Producer (plants) → consumers (animals) → decomposers (break down the dead).

Example 2

In an ecological pyramid, why are there far fewer eagles than grass?

Energy passes up the chain, but a lot is lost at each step.

So less energy reaches the top, supporting fewer animals; that is why the pyramid narrows upward.

▸ Energy decreases at each step up, so there are fewer top animals

The base (producers) is largest; if it disappears, the upper levels cannot survive.

Unit-test style

Which statement about ecosystems is correct?

①A producer hunts and eats other animals

②Plants are producers that make their own food by photosynthesis

③In an ecological pyramid there are more organisms at the top than the bottom

④Decomposers only eat living animals

⑤If one level of a food chain disappears, other organisms are unaffected

▸ ② Plants are producers that make their own food by photosynthesis

Plants make their own food by photosynthesis, so they are producers at the base of the food chain.

A producer does not hunt (①), the pyramid is wider at the bottom (③), decomposers break down dead things (④), and losing one level affects the others (⑤).

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Plant Structure & Function

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