BRAINCAKEEcosystems and material cycles
Revision notes for Ecosystems and material cycles in Edexcel Combined Science (1SC0). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Levels of organisation in an ecosystemLiving things can be studied at different levels of organisation.
- Abiotic and biotic factorsThe living things in a community are affected by abiotic (non-living) factors and by biotic (living) factors.
- Interdependence in a communityThe organisms in a community depend on each other in many ways.
- Parasitism and mutualismThe survival of some organisms depends on a close relationship with another species.
- Core practical: quadrats and belt transectsField-work lets us investigate how the number of organisms in a habitat is related to the environment.
- Estimating population size from quadrat dataCounting every organism in a large area is not practical, so we sample with quadrats and scale up.
- Positive and negative human interactions with ecosystems: fish farming and non-indigenous speciesHuman activity can help or harm ecosystems.
- Benefits of maintaining biodiversity, conservation and reforestationBiodiversity is the variety of different species living in an ecosystem.
- How materials cycle through the abiotic and biotic parts of an ecosystemThe materials that living things are made from, such as carbon and nitrogen, are not made new.
- The carbon cycle and the role of decomposersCarbon is found in all the compounds that make up living things, such as carbohydrates, fats and proteins.
- The water cycle and the production of potable waterThe water cycle moves water between the sea, the air, the land and living things.
- How nitrates become available to plants: the nitrogen cycle, fertilisers and crop rotationPlants need nitrates from the soil to make proteins.