Key term
Edexcel GCSE Combined Science Biology 1SC0
Key Concepts in Biology
Topic overviewEukaryotic and prokaryotic cellsSpecialised cells and their adaptationsMicroscopes and magnification calculationsSize, scale and units in cell biologyEnzyme action and denaturationFactors affecting enzyme activityEnzymes in synthesis and digestion, and rate calculationsDiffusion, osmosis and active transportOsmosis in potatoes and percentage change in mass
Cells and Control
Genetics
Topic overviewMeiosis and the formation of gametesDNA structure, genes and the genomeExtracting DNA from fruitAlleles, genotype and phenotypeMonohybrid crosses and sex determinationProbability and ratios from genetic crossesCauses of variation: genes and environmentThe Human Genome ProjectGenetic variation and the effects of mutation
Natural Selection and Genetic Modification
Health, Disease and the Development of Medicines
Topic overviewHealth, disease and susceptibilityPathogens and common infectionsHow pathogens spread, and the virus life cycleSexually transmitted infectionsPhysical barriers and chemical defencesThe immune system, immunisation and herd immunityAntibiotics and developing new medicinesLifestyle factors and non-communicable diseaseTreatments for cardiovascular disease
Plant Structures and Their Functions
Animal Coordination, Control and Homeostasis
Exchange and Transport in Animals
Topic overviewWhy multicellular organisms need exchange surfacesAlveoli and gas exchangeThe blood and its componentsArteries, veins and capillariesThe heart and the circulatory systemCellular respiration as an exothermic reactionAerobic and anaerobic respiration comparedInvestigating the rate of respirationCardiac output, stroke volume and heart rate
Ecosystems and Material Cycles
Ecosystems and Material Cycles
- 8 subtopics
- 24 things to know
- Paper 2
What Ecosystems and Material Cycles covers
Ecosystems and Material Cycles is examined in Paper 2, Biology 2. It covers levels of organisation and interdependence, abiotic and biotic factors, parasitism and mutualism, sampling with quadrats and transects and estimating population size, human impact on biodiversity, and the carbon, water and nitrogen cycles.
Where it is assessed
Paper 2
Biology 2: Biology in Combined Science: 1 hour 10 minutes, 60 marks, 16.67% of the qualification.
Check the Pearson Edexcel specification ↗The 8 subtopics
Each one has its own page.
- Levels of organisation and interdependenceIndividuals, populations, communities, habitats and ecosystems and their order, interdependence through food, shelter, pollination and seed dispersal, how losing one species affects others in a food web, and why an interdependent community stays balanced.Open →
- Abiotic and biotic factors in a communityAbiotic and biotic factors, how temperature, light, drought and pollution shape a community, what plants and animals compete for, and the cycle of predator and prey numbers.Open →
- Parasitism and mutualismParasitism and mutualism, with tapeworms, fleas and mistletoe as parasites, and oxpeckers and buffalo, cleaner fish, nitrogen-fixing bacteria in pea plants, and chemosynthetic bacteria in deep-sea tube worms as mutualistic partners.Open →
- Sampling with quadrats and transectsUsing random quadrats to find the mean number of a plant per square metre, generating random coordinates, percentage cover, belt transects across a changing habitat, measuring light and soil moisture, sample size and sources of error, and the mean, median and mode of quadrat counts.Open →
- Estimating population size from field dataScaling a quadrat mean up to a whole site, working the mean per square metre from quadrats of different sizes, why the result is only an estimate, and transect counts.Open →
- Human impact on ecosystems and biodiversityBiodiversity, the harm and benefits of fish farming, non-indigenous species and their effects on native wildlife, eutrophication from fertiliser and sewage, why biodiversity keeps ecosystems stable, conserving endangered species through captive breeding and protected habitats, reforestation, and the economic value of biodiversity.Open →
- The carbon cycleWhy materials must be recycled, the biotic and abiotic parts of material cycles, decomposers, and the carbon cycle, with photosynthesis removing carbon dioxide, respiration and combustion returning it, carbon passing along food chains, and the effects of burning fossil fuels and clearing forests.Open →
- The water and nitrogen cyclesEvaporation, transpiration, condensation and precipitation in the water cycle, potable water and desalination by distillation, why sea water dehydrates, and the nitrogen cycle, with nitrogen-fixing, nitrifying and denitrifying bacteria, decomposers, legume crop rotation, fertilisers and draining waterlogged soil.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Describe how sea water is made into potable water and why untreated sea water dehydrates a person.
Process
Describe the sequence of events in eutrophication after fertiliser runs off a field into a lake.
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What is a population?
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What is an abiotic factor?
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What is parasitism?
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What is a quadrat?
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State the rule used to estimate the total number of plants in an area from quadrat data.
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Explain why materials must be recycled within an ecosystem.
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What is a community?
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What is a biotic factor?
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What is mutualism?
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Describe how quadrats are used to find the mean number of daisies per square metre in a field.
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Ten quadrats of 1 m² placed in a 500 m² field contain 45 dandelions in total. Estimate the number of dandelions in the field.
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What is biodiversity?
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Name three elements that cycle between the living and non-living parts of an ecosystem.
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What is an ecosystem?
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Explain how a fall in temperature can reduce the size of an insect population.
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Mistletoe grows attached to the branches of a tree. Explain why this is parasitism.
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Explain why quadrat positions must be chosen at random when sampling an area of even habitat.
Numbers
Twenty quadrats, each of area 0.25 m², contain 60 buttercup plants altogether. Calculate the mean number of buttercups per square metre.
Key term
Describe two ways in which fish farming can damage the surrounding ecosystem.
Key term
Describe the general path a material follows as it cycles through an ecosystem.
Process
Name the two processes that move water from the Earth's surface into the air.
Take Ecosystems and Material Cycles 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 in a place at one time. Community: all the different species living together in one habitat.
Abiotic factor vs Biotic factor
Abiotic factor: non-living condition of the environment affecting organisms. Biotic factor: effect on an organism caused by other living organisms.
Parasitism vs Mutualism
Parasitism: one organism lives on a host, taking what it needs and harming it. Mutualism: relationship in which both organisms gain a benefit.
Questions from this topic
Each one with the model answer underneath.
- 1
What is a population?
Model answer
A population is all the organisms of one species living in the same place at the same time.
- 2
What is a community?
Model answer
A community is all the populations of the different species living together in one habitat.
- 3
What is an ecosystem?
Model answer
An ecosystem is a community of organisms together with the non-living surroundings they interact with.
- 4
What is a habitat?
Model answer
A habitat is the particular place in which an organism lives.
- 5
Place the terms community, individual organism, ecosystem and population in order from the smallest level of organisation to the largest.
Model answer
Individual organism, then population, then community, then ecosystem.
- 6
A wood contains 300 oak trees, 40 badgers and several thousand woodlice. Which level of organisation do the 40 badgers represent?
Model answer
They are a population, because they are all members of one species living in the same place.
What is inside Levo
Six ways to work the same material.
Ecosystems and Material Cycles revision questions
- What does Ecosystems and Material Cycles cover in Edexcel GCSE Combined Science Biology?
- 8 subtopics: levels of organisation and interdependence, abiotic and biotic factors in a community, parasitism and mutualism, sampling with quadrats and transects, estimating population size from field data, human impact on ecosystems and biodiversity, the carbon cycle and the water and nitrogen cycles. Each one has its own page with questions and model answers.
- How is Ecosystems and Material Cycles organised?
- By the Edexcel 1SC0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Ecosystems and Material Cycles, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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