Ecology

What Ecology covers

Ecology is examined in Biology Paper 2. It covers levels of organisation in an ecosystem and what organisms need; competition, interdependence and stable communities; abiotic and biotic factors and adaptations; food chains, predators and prey, and sampling with quadrats and transects; how materials are cycled; and waste management, land use, deforestation, global warming and maintaining biodiversity.

The 11 subtopics

Each one has its own page.

• Levels of organisation in an ecosystem, and what organisms needPopulation, community, habitat and ecosystem, biotic and abiotic parts, what plants and animals must obtain to survive, and competition and adaptation in rock pools, deserts and streams.Open →
• Competition, interdependence and stable communitiesWhat plants and animals compete for, with seedlings under trees and fighting deer, interdependence and what species depend on each other for, stable communities, the effects of losing bees or a single species, and reading producers and competition from tables.Open →
• Abiotic factorsThe seven abiotic factors, dissolved oxygen in water, soil pH and minerals, wind direction, and how moisture, warming, acid rain, shelter and light change a community.Open →
• Biotic factorsFood availability, new predators, new pathogens and competition as biotic factors, with red and grey squirrels, poor acorn crops, island prey, lost plant species and diseased ash trees, and interpreting population data on introduced species and disease.Open →
• AdaptationsStructural, behavioural and functional adaptations, extremophiles such as deep sea vent bacteria and their enzymes, and examples including whale blubber, camel urine, Arctic fox ears and cactus spines and stems.Open →
• Producers, food chains and sampling with quadrats and transectsProducers and biomass, why a producer starts every food chain and what the arrows mean, quadrats and transects, distribution against abundance, and the mean, median and mode of counts.Open →
• Predators, prey and measuring population sizePrimary, secondary and tertiary consumers, predators and prey and their cycling numbers, estimating a field's dandelions with random quadrats, and using a transect along a footpath.Open →
• How materials are cycledWhy materials must be recycled, the carbon cycle through photosynthesis, respiration, combustion and decomposers, the water cycle through evaporation, condensation and precipitation, and the role of microorganisms in returning carbon dioxide and mineral ions.Open →
• Waste management and biodiversityWhy a growing population and rising living standards produce more waste, sources of water, air and land pollution, how fertiliser, acid rain and toxic chemicals damage ecosystems, and what biodiversity is, why it makes ecosystems stable and how human activity has reduced it.Open →
• Land use, deforestation and global warmingLand lost to building, quarrying, farming and waste, peat bog destruction and the carbon dioxide it releases, tropical deforestation for cattle, rice and biofuels, carbon dioxide and methane in global warming, and its effects on species distribution and sea levels.Open →
• Maintaining biodiversityBreeding programmes, habitat protection, field margins and hedgerows, recycling and cutting deforestation and carbon dioxide emissions, negative and positive human interactions with ecosystems, and the conflicts that conservation programmes can cause.Open →

What you need to know

Answer each one before you reveal it.

Take Ecology further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Population vs Community

  Population: all the organisms of one species living in the same habitat. Community: all the different species living and interacting in the same habitat.

• Habitat vs Ecosystem

  Habitat: the place in which an organism lives. Ecosystem: a community of living organisms interacting with the non-living parts of their environment.

• Biotic factor vs Abiotic factor

  Biotic factor: a living influence on a community, such as predators, pathogens or competition. Abiotic factor: a non-living condition such as light intensity, temperature or soil pH.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is meant by a population in an ecosystem?

   Model answer

   All the organisms of one species living in the same habitat at the same time.

2. 2

   What is meant by a community?

   Model answer

   All the populations of the different species that live in the same habitat and interact with each other.

3. 3

   List the levels of organisation in an ecosystem in order, starting with the smallest.

   Model answer

   Individual organism, then population, then community, then the whole ecosystem.

4. 4

   What is a habitat?

   Model answer

   The place in which an organism lives.

5. 5

   What is an ecosystem?

   Model answer

   The interaction of a community of living organisms with the non-living parts of their environment.

6. 6

   An ecosystem has biotic and abiotic parts. What does each of these words mean?

   Model answer

   Biotic parts are the living organisms; abiotic parts are the non-living physical and chemical conditions.

What is inside Levo

Six ways to work the same material.

Ecology revision questions

What does Ecology cover in AQA GCSE Combined Science Biology?

11 subtopics: levels of organisation in an ecosystem, and what organisms need, competition, interdependence and stable communities, abiotic factors, biotic factors, adaptations, producers, food chains and sampling with quadrats and transects, predators, prey and measuring population size, how materials are cycled, waste management and biodiversity, land use, deforestation and global warming and maintaining biodiversity. Each one has its own page with questions and model answers.

How is Ecology organised?

By the AQA 8464 specification, subtopic by subtopic, so it matches the order you are taught it in.