Key term
Edexcel GCSE Biology 1BI0
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 calculationsFood tests and the energy in foodDiffusion, osmosis and active transportOsmosis in potatoes and percentage change in mass
Cells and Control
Topic overviewMitosis and the cell cycleWhy mitosis matters: growth, repair and cancerGrowth, differentiation and percentile chartsStem cells and their use in medicineThe structure and function of the brainInvestigating and treating the brainNeurones, receptors and the reflex arcThe structure and function of the eyeEye defects and how they are corrected
Genetics
Topic overviewAsexual and sexual reproductionMeiosis and the formation of gametesDNA structure, genes and the genomeExtracting DNA from fruitProtein synthesis: transcription and translationGenetic variants in coding and non-coding DNAMendel's work and the inheritance of blood groupsAlleles, genotype and phenotypeMonohybrid crosses and sex determinationProbability and ratios from genetic crossesSex-linked disordersCauses of variation: genes and environmentThe Human Genome ProjectGenetic variation and the effects of mutation
Natural Selection and Genetic Modification
Topic overviewDarwin, Wallace and the theory of evolutionNatural selection and antibiotic resistanceFossil evidence for human evolutionStone tool evidence for human evolutionThe pentadactyl limb and the three domainsSelective breedingTissue cultureGenetic engineering and modern agricultureThe stages of genetic engineeringBenefits and risks of GM organisms
Health, Disease and the Development of Medicines
Topic overviewHealth, disease and susceptibilityPathogens and common infectionsHow pathogens spread, and the virus life cycleSexually transmitted infectionsHow plants defend themselves and how plant disease is detectedPhysical barriers and chemical defencesThe immune system, immunisation and herd immunityAntibiotics and developing new medicinesAseptic technique in culturing microorganismsTesting antiseptics and antibiotics on bacterial culturesMonoclonal antibodiesLifestyle factors and non-communicable diseaseTreatments for cardiovascular disease
Plant Structures and Their Functions
Topic overviewPhotosynthesis as an endothermic reactionLimiting factors in photosynthesisLight intensity and the rate of photosynthesisRoot hair cells, xylem and phloemTranspiration and translocationLeaf structure for photosynthesis and gas exchangeFactors affecting the rate of transpirationPlant adaptations to extreme environmentsPlant hormones and their commercial uses
Animal Coordination, Control and Homeostasis
Topic overviewHormones, endocrine glands and homeostasisAdrenalin, thyroxine and negative feedbackThe menstrual cycle and its hormonesHormonal and barrier contraceptionAssisted reproductive technology and IVFHomeostasis and thermoregulationControlling blood glucose, and type 1 diabetesType 2 diabetes and body massThe urinary system and the production of ureaThe nephron, filtration and the effect of ADHTreating kidney failure: dialysis and transplants
Exchange and Transport in Animals
Topic overviewWhy multicellular organisms need exchange surfacesAlveoli and gas exchangeRate of diffusion and Fick's lawThe 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
Topic overviewLevels of organisation and interdependenceAbiotic and biotic factors in a communityParasitism and mutualismSampling with quadrats and transectsEstimating population size from field dataEnergy transfer between trophic levelsHuman impact on ecosystems and biodiversityFood securityThe carbon cycleThe water and nitrogen cyclesIndicator species and pollutionFactors affecting the rate of decompositionCalculating the rate of decay
Ecosystems and Material Cycles
- 13 subtopics
- 39 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, energy transfer between trophic levels, human impact on biodiversity, food security, the carbon, water and nitrogen cycles, indicator species, and the factors affecting decomposition and calculating the rate of decay.
Where it is assessed
Paper 2
Biology 2: 1 hour 45 minutes, 100 marks, 50% of the GCSE.
Check the Pearson Edexcel specification ↗The 13 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 →
- Energy transfer between trophic levelsTrophic levels, the energy lost as heat, faeces and urine, why food chains stay short, pyramids of biomass, and calculating the percentage efficiency of a transfer.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 →
- Food securityFood security and how a rising population, increasing meat consumption, overfishing, new pests and pathogens, environmental change, biofuel crops and the rising cost of fertiliser and fuel all threaten it.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 →
- Indicator species and pollutionIndicator species, the bloodworms, sludgeworms, freshwater shrimps and stonefly nymphs that show polluted or clean water, lichens and blackspot fungus as indicators of sulfur dioxide in the air, and the advantages and limitations of using indicator species.Open →
- Factors affecting the rate of decompositionThe warmth, water and oxygen that decay microorganisms need, how refrigeration, freezing, drying, salting, vacuum packing and canning preserve food, and how turning, heat, moisture, shredding and temperature affect the rate of decay in a compost heap.Open →
- Calculating the rate of decayMean rate of decay from mass lost over time, comparing rates at two temperatures, mass remaining after a period or after a percentage loss, and why decay slows later.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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Explain why crops need nitrogen compounds from the soil and how a farmer keeps the supply up.
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Explain how surface area and temperature affect the rate of decay in a compost heap.
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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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What is a trophic level?
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What is meant by food security?
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Explain why materials must be recycled within an ecosystem.
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What is an indicator species?
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How is the mean rate of decay of a sample calculated from its change in mass?
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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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State three ways in which energy is lost at a trophic level instead of being passed on.
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What is biodiversity?
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Explain how a rising human population threatens food security.
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Name three elements that cycle between the living and non-living parts of an ecosystem.
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Name two invertebrates whose presence in a river indicates that the water is polluted.
Numbers
A 40 g sample of grass cuttings decays at a mean rate of 1.6 g per day. Calculate the mass remaining after 5 days.
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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.
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Explain why food chains rarely contain more than four or five trophic levels.
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Describe two ways in which fish farming can damage the surrounding ecosystem.
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Explain how overfishing threatens future food supplies.
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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.
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Name two invertebrates found in clean, well-oxygenated fresh water.
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Which organisms are responsible for food decaying?
Numbers
A 120 g sample of grass cuttings has lost 45% of its mass after three weeks. Calculate the mass remaining.
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 Biology?
- 13 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, energy transfer between trophic levels, human impact on ecosystems and biodiversity, food security, the carbon cycle, the water and nitrogen cycles, indicator species and pollution, factors affecting the rate of decomposition and calculating the rate of decay. Each one has its own page with questions and model answers.
- How is Ecosystems and Material Cycles organised?
- By the Edexcel 1BI0 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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