IGCSE Biology

Describe how endangered species can be conserved, limited to: (a) monitoring and protecting species and habitats (b) education (c) captive breeding programmes (d) seed banks

Explain why organisms become endangered or extinct, including: climate change, habitat destruction, hunting, overharvesting, pollution and introduced species

State that some resources can be conserved and managed sustainably, limited to forests and fish stocks

Describe a sustainable resource as one which is produced as rapidly as it is removed from the environment so that it does not run out

Explain the process of eutrophication of water, limited to: • increased availability of nitrate and other ions • increased growth of producers • increased decomposition after death of producers • increased aerobic respiration by decomposers • reduction in dissolved oxygen • death of organisms requiring dissolved oxygen in water

Describe the sources and effects of pollution of the air by methane and carbon dioxide, limited to: the enhanced greenhouse effect and climate change

Describe the effects of non-biodegradable plastics, in both aquatic and terrestrial ecosystems

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