(a(i))[3]
Use the information in Fig. 5.1 to state each of the following: • the trophic level of the aquatic plant • the trophic level of the fish • the chemical element that is being cycled in this ecosystem.
(a(ii))[2]
Explain one way, apart from food, in which the fish may depend on the aquatic plant.
(b(i))[2]
Name the processes represented by the letters X and Y.
(b(ii))[1]
Name one type of microorganism that will carry out both process X and process Y.
(b(iii))[3]
Explain how aquatic plants take up nitrate ions from their surroundings.
(c)[2]
Suggest what effect pollution by nitrogen-containing fertilisers might have on this ecosystem.