(a)[4]
On Fig. 5.1, identify a quaternary consumer, a herbivore, an organism that is both a secondary consumer and a tertiary consumer, and an organism at trophic level one.
(b(i))[2]
Draw the pyramid of biomass for this food chain and label the pyramid with the name of each species.
(b(ii))[1]
State the main source of energy for food webs.
(b(iii))[3]
Explain how each of the two possible changes in the road runner population could happen.
(c(i))[2]
Explain why farmers make use of insecticides.
(c(ii))[3]
Suggest three further ways in which humans may lead the population of birds such as hawks to decline.