Ecosystems — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Living things in an ecosystem such as plants and animals are called biotic factors.
Biotic factors are all living components: plants, animals, fungi, bacteria.
2. Non-living things like water, sunlight, and soil are called abiotic factors.
Abiotic factors are non-living: temperature, water, sunlight, soil, air.
3. A food web shows many overlapping food chains in one ecosystem.
A food web is a complex diagram showing all feeding relationships in an ecosystem.
4. Temperature is an abiotic factor that affects which organisms can survive in an area.
Temperature is non-living, so it is an abiotic factor. It determines habitat suitability.
5. Bacteria in the soil are biotic factors because they are living organisms.
Bacteria are alive, making them biotic factors in the ecosystem.
6. A food web is more complex than a single food chain because it shows all feeding links.
A food web shows multiple interconnected food chains, giving a more complete picture of an ecosystem.
7. If one species disappears from a food web, other species that depend on it are affected.
Species in food webs are interdependent. Removing one can cause a cascade of effects throughout.
8. The amount of rainfall an area receives determines what types of plants can grow there.
Precipitation is a key abiotic factor that determines plant communities and thus entire ecosystems.
9. An ecosystem includes both biotic and abiotic factors working together as a system.
An ecosystem is a system where living and non-living parts interact and depend on each other.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Sunlight
→ Abiotic — provides energy that producers need to make food
Abiotic — provides minerals and a place for roots to grow
Fungi
→ Biotic — breaks down dead matter and recycles nutrients
Biotic — breaks down dead matter and recycles nutrients
Soil
→ Abiotic — provides minerals and a place for roots to grow
Biotic — produces acorns and oxygen through photosynthesis
Oak tree
→ Biotic — produces acorns and oxygen through photosynthesis
Abiotic — provides energy that producers need to make food
Sunlight=abiotic energy for producers(idx3); Fungi=biotic decomposer(idx1); Soil=abiotic minerals for roots(idx0); Oak tree=biotic producer(idx2)