Edexcel International GCSE Science (Double Award), topic 4
Ecology and the environment
Ecology is the study of how organisms interact with each other and with their environment. This topic covers how populations are studied and what affects them, how energy and substances pass along food chains, how the carbon cycle recycles materials, and how human activities such as pollution affect the environment.
Revision notes
Worksheet
FlashcardsSubtopics
Work through them in order. Each one has notes, exam questions and flashcards, and a PDF of each. Biology-only subtopics are left out.
- 1The organism in the environment Spec 4.1–4.5Population, community, habitat and ecosystem, estimating population size with quadrats, and how abiotic and biotic factors affect populations.NotesQuestions 5Flashcards 12
- 2Feeding relationships Spec 4.6–4.9Trophic levels, food chains and webs, pyramids of number, biomass and energy, and why only about 10% of energy passes to the next level.NotesQuestions 7Flashcards 14
- 3Cycles within ecosystems Spec 4.10–4.11BThe carbon cycle: how photosynthesis, respiration, combustion and decomposers move carbon between living things and the air.NotesQuestions 3Flashcards 4
- 4Human influences on the environment Spec 4.12–4.18BAir pollution by sulfur dioxide and carbon monoxide, greenhouse gases and global warming, water pollution by sewage, and eutrophication.NotesQuestions 6Flashcards 15
Whole topic
When you have done the subtopics: test yourself on everything, or print the lot.