Using a plastic drink bottle we can devise ecosystems in our laboratories.
Construct the ecosystem above.
Describe the inter-relationships between all the organisms present.
Use the words :
Photosynthesis
Respiration
Food chain
Oxygen
Carbon dioxide
Solar energy
Chemical energy.
Eutrophication is the polluting of streams and lakes by the over use of fertilisers. Farmers use fertilisers which wash into rivers and lakes and build up. Algae grows in the nutritious water and blocks sunlight reaching the plants below. Eventually all the fish and plants will die. Explain why? Use the following words and reactions in your explanation.

Bacteria and fungi

carbon dioxide + water --> glucose + oxygen.
glucose + oxygen --> carbon dioxide + water