(a)[2]
State the name of one organism shown in Fig. 6.1 that is a primary consumer, and one organism that is both a secondary consumer and a tertiary consumer.
(b)[2]
Use the information in Fig. 6.1 to state which of these would be the least energy efficient for humans to eat and explain why.
(c(i))[3]
Suggest the effects on this ecosystem of a larger mass of Nile tilapia being removed from the lake by human fishing.
(c(ii))[5]
Suggest and explain ways in which the fish populations in the Lake Victoria ecosystem could be managed so that they remain a sustainable resource.
(d)[5]
Describe the similarities and differences between the human and Nile perch circulatory and respiratory systems.