IB Biology SL 4.2.22 Decomposers and nutrient cycling Question Bank
Practise IB Biology SL 4.2.22 by explaining how decomposers recycle matter in ecosystems.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Practise IB Biology SL 4.2.22 by explaining how decomposers recycle matter in ecosystems.
The bar chart shows the mass of animal feed required to produce one kilogram of meat, egg or milk (kg dry matter in feed per kg of output).

Feed conversion ratio / kg dry matter in feed per kg of output
Outline two ways in which agricultural production of animals may change the cycling of nutrients (for example phosphorous or nitrogen) in ecological systems.
a. animals remove nutrients from systems by feeding/being eaten;
b. nutrients added to systems by fertilizers/manure;
c. fertilizer/manure/organic matter run-off can affect other ecosystems;
d. deforestation results in leaching/loss of nutrients;
e. pesticides may affect decomposers;
2 max