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O-Level Organisms and their Environment

What the O-Level syllabus expects for Organisms and their Environment, and how to practise it.

What the syllabus expects

Set out how energy flow is non-cyclical.
Set out the parts played by producers, consumers and decomposers within food chains and food webs.
Account for where energy is lost along food chains, and talk through how efficiently energy passes from one trophic level to the next.
Set out and read pyramids of numbers and of biomass.
Set out how carbon moves around within an ecosystem and outline the part that forests and oceans play as carbon sinks.
Set out how human activities like deforestation and burning fossil fuels raise the level of carbon dioxide in the atmosphere and thereby drive global warming.
Talk through the actions people can take to lessen the effects of global warming.
Set out the effects of pollution from sewage in water, from plastic waste in the marine environment, and from insecticides that biomagnify up food chains and impact top carnivores.
Talk through how conserving species and using natural resources sustainably help keep biodiversity and a balanced ecosystem, for example in coral reefs, tropical rainforests and mangroves.