- A microorganism is a kind of decomposer
- A bacterium is a kind of decomposer
- Therefore, bacteria and microorganisms are kinds of decomposers

- Bacteria and microorganisms are kinds of decomposers
- Decomposition is when a decomposer recycles / returns nutrients / nitrogen from dead organisms to the soil by eating those dead organisms
- Therefore, bacteria and microorganisms return nutrients from dead organisms to the soil

- Bacteria and microorganisms return nutrients from dead organisms to the soil
- Soil is usually part of an environment
- Therefore, bacteria and microorganisms return nutrients from dead organisms to the environment

- Bacteria and microorganisms return nutrients from dead organisms to the environment
- A living thing requires nutrients for survival
- So, living things require bacteria and microorganisms to return nutrients to the environment

Therefore, living things require bacteria and microorganisms to return nutrients to the environment
Q: Which of these living things in a grassland ecosystem depend on the presence of a variety of bacteria and other microorganisms in the soil?
Context:
- Soil is usually part of an environment 
- Decomposition is when a decomposer recycles / returns nutrients / nitrogen from dead organisms to the soil by eating those dead organisms 
- A microorganism is a kind of decomposer 
- A living thing requires nutrients for survival 
- A bacterium is a kind of decomposer