Ecosystems

5 lessons in Ecology.

27 exam questions · 57 marks

7.1 Communities and interdependence The levels of organisation in an ecosystem (individual, population, community, ecosystem), what organisms compete for, interdependence and stable communities, and (Edexcel and OCR) parasitism and mutualism. AQA Edexcel OCR 6 questions 7.2 Abiotic and biotic factors The non-living (abiotic) and living (biotic) factors that affect communities, with examples of how a change in each can change the size and distribution of populations. AQA Edexcel OCR 5 questions 7.3 Adaptations AQA: how organisms are adapted to their environment through structural, behavioural and functional adaptations, and extremophiles that live in very hot, salty or high-pressure places. AQA 5 questions 7.4 Food chains and predator-prey cycles How food chains show feeding relationships from producers to primary, secondary and tertiary consumers, why producers are the source of all biomass, and why predator and prey populations rise and fall in linked cycles. AQA Edexcel OCR 5 questions 7.5 Required practical: sampling with quadrats and transects The required practical on sampling: using random quadrats to estimate a population, belt transects to see how distribution changes with an abiotic factor, calculating mean, median and mode, and (OCR) capture-recapture, pooters, sweep nets and pitfall traps. AQA Edexcel OCR 6 questions