Questions and Answers

Describe the effects of untreated sewage and excess fertiliser on aquatic ecosystems

Describe the advantages and disadvantages of intensive livestock production

Describe the advantages and disadvantages of large-scale monocultures of crop plants

Describe how humans have increased food production, limited to: (a) agricultural machinery to use larger areas of land and improve efficiency (b) chemical fertilisers to improve yields (c) insecticides to improve quality and yield (d) herbicides to reduce competition with weeds (e) selective breeding to improve production by crop plants and livestock

Explain the factors that lead to each phase in the sigmoid curve of population growth, making reference, where appropriate, to the role of limiting factors

Interpret graphs and diagrams of population growth

Identify the lag, exponential (log), stationary and death phases in the sigmoid curve of population growth for a population growing in an environment with limited resources

Describe an ecosystem as a unit containing the community of organisms and their environment, interacting together

Describe a community as all of the populations of different species in an ecosystem

Describe a population as a group of organisms of one species, living in the same area, at the same time