Ecosystems
Grade 4 · Science · Study Guide
Discover how living things and their environment work together as a system.
An ecosystem is all the living things in an area plus the non-living parts of their environment working together. Living parts are called biotic factors — they include plants, animals, fungi, and bacteria. Non-living parts are called abiotic factors — they include sunlight, water, soil, temperature, and air.
Every ecosystem has producers, consumers, and decomposers. Producers are plants and algae that make their own food using sunlight through a process called photosynthesis. Consumers are animals that eat other living things. Herbivores eat only plants, carnivores eat only animals, and omnivores eat both. Decomposers like mushrooms and bacteria break down dead material and return nutrients to the soil.
Ecosystems come in many types called biomes. A forest biome gets lots of rain and has tall trees. A desert biome is very dry and hot during the day. A grassland biome has few trees but lots of grasses. An ocean biome covers most of Earth and is home to millions of species. Each biome has organisms specially adapted to survive there.
| Consumer Type | What They Eat | Example |
|---|---|---|
| Herbivore | Only plants | Rabbit, cow, caterpillar |
| Carnivore | Only animals | Wolf, eagle, shark |
| Omnivore | Plants and animals | Bear, human, raccoon |
Key terms
- Ecosystem
- All living and non-living things in an area interacting together
- Biotic
- The living parts of an ecosystem such as plants and animals
- Abiotic
- The non-living parts of an ecosystem such as water, sunlight, and soil
- Producer
- An organism that makes its own food using sunlight — plants and algae
- Consumer
- An organism that gets energy by eating other organisms
- Decomposer
- An organism that breaks down dead material and recycles nutrients
Flashcards
- Ecosystem
- All living and non-living things in an area working together
- Biotic
- Living parts of an ecosystem
- Abiotic
- Non-living parts of an ecosystem like water and sunlight
- Producer
- Makes its own food using sunlight (plants, algae)
- Consumer
- Eats other organisms for energy
- Decomposer
- Breaks down dead material to recycle nutrients
Practice questions
What are the non-living parts of an ecosystem called?
- Biotic factors
- Abiotic factors
- Producers
- Consumers
Show answer
Answer: Abiotic factors
Abiotic factors are the non-living components of an ecosystem such as water, sunlight, soil, and temperature.
Which organism is a producer?
- A wolf
- A mushroom
- A sunflower
- A deer
Show answer
Answer: A sunflower
Sunflowers are producers because they make their own food through photosynthesis using sunlight.
Decomposers help recycle nutrients back into the soil.
Show answer
Answer: True
Decomposers like fungi and bacteria break down dead organisms and release nutrients back into the soil for plants to use.
A carnivore eats only plants.
Show answer
Answer: False
A carnivore eats only animals. An animal that eats only plants is called a herbivore.
An animal that eats both plants and animals is called an ___.
Show answer
Answer: omnivore
Omnivores eat both plants and animals. Bears and raccoons are examples of omnivores.
Fun facts
- A single oak tree can be home to over 500 different species of insects!
- The Amazon rainforest produces about 20% of the world's oxygen.
- Decomposers are nature's recyclers — without them, Earth would be buried in dead matter.
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