- Green plants are made of plant cells
- Green plants are a kind of producer
- So, green plants as producers are made of plant cells

- A chloroplast is a kind of plant cell structure
- A plant cell contains chloroplasts
- Hence, a plant cell contains a strucutre called chloroplast

- Green plants as producers are made of plant cells
- A plant cell contains a strucutre called chloroplast
- Therefore, chloroplasts are the structure that is in the cells of producers

So, chloroplasts are the structure that is in the cells of producers
Question: Which structure is found in producers in nearly all ecosystems?
Context: - A chloroplast is a kind of plant cell structure 
- A plant cell contains chloroplasts 
- Green plants are made of plant cells 
- Green plants are a kind of producer