Process
Edexcel A-Level Biology A 9BN0
Lifestyle, Health and Risk
Topic overviewWater and the carbohydratesCondensation, hydrolysis and glycosidic bondsLipids, food tests and unitsThe cardiac cycle and the structure of the heartArteries, veins and capillariesCore practical: caffeine and the heart rate of DaphniaThe blood clotting cascadeThrombus, embolus and their consequencesAtherosclerosis and the risk factors for CVDTreatments for CVD, and cholesterol transportBMI, waist-to-hip ratio and energy balanceCore practical 2: the vitamin C content of food and drinkCorrelation, causation and the design of health studiesRisk perception, and handling quantitative data
Genes and Health
Topic overviewGas exchange surfaces and Fick's LawThe fluid mosaic model of the cell membraneOsmosis, diffusion and active transportSurface area and volume calculationsThe structure of DNA and RNATranscriptionTranslation and the genetic codeAmino acids and the levels of protein structureGlobular and fibrous proteins: haemoglobin and collagenAlternative splicing and tissue-specific proteinsEnzyme specificity, the active site and activation energyRates of reaction, Vmax and Core Practical 4Semi-conservative replication and Meselson-StahlTypes of mutation and the CFTR geneAlleles, genotype and monohybrid inheritancePedigree diagrams and the inheritance of cystic fibrosisThe effects of cystic fibrosis, and the chi-squared testPrenatal genetic testing: PGD, amniocentesis and CVSThe ethics of genetic screening
Voice of the Genome
Topic overviewProkaryotic cellsEukaryotic organelles and their functionsIdentifying organelles in an electron micrographProtein secretion, and levels of organisationMicroscopy: the graticule, magnification and standard formThe cell cycle and the stages of mitosisCore practical: the root tip squashMeiosis, linkage and sex linkageThe structure of sperm and egg cellsFertilisation: the acrosome and cortical reactionsTotipotency, pluripotency and sources of stem cellsThe ethics and risks of stem cell therapyDifferential gene expression and specialisationThe lac operonEpigenetics: DNA methylation and histone modificationPolygenic inheritance, continuous variation and statistics
Biodiversity and Natural Resources
Topic overviewBiodiversity, species richness and the index of diversityNiches and the three kinds of adaptationNatural selection and evolutionThe Hardy-Weinberg equation and its assumptionsReproductive isolation and speciationClassificationThe plant cell wall, chloroplast and amyloplastThe vacuole, plasmodesmata, pits and middle lamellaPlant cells in the electron microscopeStarch and celluloseLignin, xylem vessels and sclerenchyma fibresIdentifying plant tissues under the microscopeThe structure of xylem, phloem and sclerenchymaWater and the mineral nutrition of plantsCore practical: investigating mineral deficiencyCore practical: the tensile strength of plant fibresDrug development from Withering to modern trialsGrowing bacteria and aseptic techniqueCore practical: the antimicrobial properties of plantsSustainability and Conservation
On the Wild Side
Topic overviewPhotosynthesis: the light-dependent reactionsPhotosynthesis: the Calvin cycleChloroplast structure and the products of photosynthesisProductivity: GPP, NPP and energy transferCore practicals on temperature and growthTemperature, enzymes and Q10Sampling: quadrats and transectsSuccessionBiotic and abiotic factors, niches and competitionEcosystem terms, evolution, speciation and validating evidenceEvidence for climate changeClimate models and their limitationsCorrelation, causation and scientific objectivityThe effects of climate change on organismsHuman activities that raise greenhouse gas levelsThe greenhouse effectEvolution and natural selectionSpeciationHow new scientific evidence is validatedThe carbon cycleReforestation, biofuels and sustainability
Immunity, Infection and Forensics
Topic overviewDecomposition, succession and forensic entomologyBody cooling and rigor mortisDNA profiling and the polymerase chain reactionGel electrophoresisThe structure of bacteria and virusesDecomposition, and how pathogens enter the bodyThe body's barriers, and modelling bacterial growthTuberculosis and HIVThe non-specific immune responseAntigens, antibodies and B cellsT cells and cell-mediated immunityActive and passive immunity, natural and artificialThe evolutionary race and pathogen evasionAntibiotics and testing their effectivenessHospital acquired infections and their control
Run for Your Life
Topic overviewMuscles and MovementThe myofibril and the sarcomereThe sliding filament theory, calcium and ATPSlow-twitch and fast-twitch muscle fibresGlycolysis and the link reactionThe Krebs cycle, oxidative phosphorylation and oxygen debtThe conduction system: SAN, AVN and Purkyne fibresThe sequence of cardiac excitationThe electrocardiogram, cardiac output and stroke volumeThe cardiovascular and ventilation control centresSpirometry and ventilation during exerciseHomeostasis, feedback and gene control by hormonesThermoregulation and the hypothalamusThe effects of too much and too little exerciseMedical technology and performance-enhancing substances
Grey Matter
Topic overviewThe structure of neurones and myelinationThe action potential and saltatory conductionThe structure of a synapse and calcium entryNeurotransmitter release and acetylcholineRod cells and the detection of lightEffectors, the neuromuscular junction and the pupil reflexPhytochrome and the response to lightIAA, phototropism and gravitropismNervous against hormonal coordinationThe regions of the brain and their functionsBrain imaging: MRI, fMRI, PET and CTCritical periods and the Hubel and Wiesel experimentsNature, nurture, habituation and research ethicsDopamine, serotonin and their imbalanceL-Dopa and MDMAGenome sequencing, personalised medicine and its ethicsGenetically modified organisms: benefits and risks
On the Wild Side
- 21 subtopics
- 63 things to know
- Papers 1 and 3
What On the Wild Side covers
Covers ecology and the climate: how ecosystems are sampled and how they change through succession, photosynthesis and productivity, the evidence for climate change and the models built from it, evolution and speciation, and the carbon cycle.
Where it is assessed
Papers 1 and 3
The Natural Environment and Species Survival, then the synoptic paper.
Check the Pearson Edexcel specification ↗The 21 subtopics
Each one has its own page.
- Photosynthesis: the light-dependent reactionsRecall questions on the excitation of chlorophyll, photophosphorylation, reduced NADP and photolysis, how their products drive the light-independent reactions, and isolating chloroplasts and measuring the Hill reaction with DCPIP.Open →
- Photosynthesis: the Calvin cycleRecall questions on carbon fixation by RuBisCO, RuBP, GP and GALP, and how RuBP is regenerated.Open →
- Chloroplast structure and the products of photosynthesisRecall questions on how light energy splits water and how its hydrogen ends up in glucose, ATP formation and hydrolysis, the respiration substrates, polysaccharides, amino acids, lipids and nucleic acids built from sugars, and the envelope, thylakoid membranes, DNA, ribosomes and lamellae of the chloroplast.Open →
- Productivity: GPP, NPP and energy transferRecall questions on gross and net primary productivity, and on calculating the efficiency of transfer between trophic levels.Open →
- Core practicals on temperature and growthRecall questions on the method and controls for the temperature and enzyme practical, the growth practical, and calculating rate from a graph.Open →
- Temperature, enzymes and Q10Recall questions on why enzyme activity rises then falls with temperature, calculating Q10, and the effect of temperature on organisms.Open →
- Sampling: quadrats and transectsRecall questions on random sampling with quadrats, systematic sampling along a transect, and measuring abiotic factors.Open →
- SuccessionRecall questions on pioneer species, seral stages, how soil and biodiversity change, and what determines the climax community.Open →
- Biotic and abiotic factors, niches and competitionRecall questions on the factors that shape where organisms live, the ecological niche, and the competitive exclusion principle.Open →
- Ecosystem terms, evolution, speciation and validating evidenceRecall questions on communities, habitats, ecosystems and populations, evolution as a change in allele frequency, mutation, fitness and natural selection, polyploidy and sympatric speciation, and how journals, peer review and conferences validate new evidence.Open →
- Evidence for climate changeRecall questions on ice cores, peat bog pollen, dendrochronology and direct temperature records.Open →
- Climate models and their limitationsRecall questions on how climate models work, and on feedback mechanisms, computing power and uncertain human behaviour as limits.Open →
- Correlation, causation and scientific objectivityRecall questions on what is needed to establish causation, extrapolation, and how funding and interest can shape conclusions.Open →
- The effects of climate change on organismsRecall questions on changes to distribution, life cycles and the timing of seasonal events, and on phenological mismatch.Open →
- Human activities that raise greenhouse gas levelsRecall questions on fossil fuels, deforestation, cement, rice paddies, cattle and landfill as sources of carbon dioxide and methane.Open →
- The greenhouse effectRecall questions on what happens to solar and infrared radiation, why the effect has been enhanced, and which gases are involved.Open →
- Evolution and natural selectionRecall questions on why some variants reproduce more, mutation as the source of new alleles, how natural selection changes allele frequencies, the conditions it requires, and the evidence for evolution from proteomics and genomics.Open →
- SpeciationRecall questions on gene flow and isolation, and on what separates allopatric from sympatric speciation.Open →
- How new scientific evidence is validatedRecall questions on what proteomics and genomics are, peer review and why reviewers are anonymous, the roles of scientific journals and conferences, and why methods are published in full.Open →
- The carbon cycleRecall questions on what the carbon cycle is, the roles of photosynthesis, respiration and decomposition, where carbon is stored as trees and biofuel crops grow, using the cycle to reduce atmospheric carbon dioxide, and carbon capture and storage.Open →
- Reforestation, biofuels and sustainabilityRecall questions on carbon sinks, why biofuels are treated as closer to carbon neutral, and on balancing human need against conservation.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Process
How does succession proceed from bare rock to woodland?
Process
How are excited electrons from chlorophyll used to produce ATP?
Key term
Explain why the light-independent reactions cannot continue indefinitely without light.
Key term
What is RuBP and what is its role in the Calvin cycle?
Key term
Describe how hydrogen atoms from water end up stored in glucose during photosynthesis.
Key term
Name one type of polysaccharide that can be synthesised from simple sugars produced in photosynthesis.
Key term
In the equation NPP = GPP − R, what does R represent?
Key term
What is the first step when setting up an investigation into the effect of temperature on enzyme activity?
Key term
After equilibrating enzyme and substrate at the required temperature, what is the next step?
Key term
What does R2 represent in the Q10 formula?
Process
How does temperature affect microorganisms and ecosystem processes?
Process
After counting organisms in multiple quadrats, how is the data processed?
Evaluation
What is systematic sampling along a transect and what does it detect?
Process
What is a sere?
Process
How does the concept of niche explain the abundance of organisms?
Key term
Define the term 'community' in an ecological context.
Process
What happens to mutations in isolated populations?
Key term
How do pollen grains preserved in peat bogs provide evidence for past climate change?
Evaluation
What do climate change models use to predict future conditions?
Evaluation
Why might feedback mechanisms limit the accuracy of climate models?
Key term
Why does correlation between two variables not prove causation?
Key term
What distinguishes a causal relationship from a mere correlation?
Process
In the greenhouse effect, what happens when solar radiation reaches Earth?
Key term
Why has the greenhouse effect been enhanced?
Evaluation
Explain how natural selection leads to changes in allele frequencies.
Process
How does proteomic evidence support the theory of evolution?
Key term
What effect does isolation have on gene flow between populations?
Key term
Where is carbon stored when trees grow?
Key term
Where is carbon stored in biofuel crops before harvesting?
Process
How do trees absorb carbon dioxide during reforestation?
Key term
What is reforestation?
Numbers
Calculate the net primary productivity when gross primary productivity = 21200 kJ m⁻² yr⁻¹, plant respiration = 17400 kJ m⁻² yr⁻¹.
Key term
How can disease function as a biotic factor?
Key term
Name two sources of evidence for climate change that relate to atmospheric carbon dioxide levels.
Key term
How does climate change affect water availability for organisms?
Key term
How does climate change affect the distribution of species?
Key term
What human activities release carbon dioxide into the atmosphere?
Key term
What are the main sources of methane emissions?
Key term
Define sympatric speciation.
Key term
Define proteomics.
Key term
Define genomics.
Key term
What happens to electrons in chlorophyll when light energy is absorbed during the light-dependent reactions?
Key term
In which cycle does carbon fixation occur during the light-independent reactions?
Key term
Why is light energy essential for the first step of photosynthesis?
Key term
What does GPP represent in the context of ecosystem productivity?
Key term
How are constant temperatures maintained when investigating the effect of temperature on enzyme activity?
Key term
Why does increasing temperature increase the rate of enzyme-catalysed reactions?
Key term
Once a quadrat is placed at a random coordinate, what data is collected?
Key term
How does soil mineral content act as an abiotic factor?
Key term
What are abiotic factors?
Key term
Define the term 'habitat'.
Key term
What two types of records provide evidence for climate change through temperature data?
Evaluation
State one limitation of climate change models relating to input data.
Key term
What is extrapolation in the context of climate data?
Key term
How does climate change affect the development and life cycles of organisms?
Key term
What is anthropogenic climate change?
Key term
What type of radiation does the Earth's surface emit after absorbing solar radiation?
Key term
Why do some variants have greater reproductive success in natural selection?
Key term
How does isolation prevent interbreeding between populations?
Key term
Define peer review in the context of scientific publication.
Key term
Where is the carbon absorbed by trees during photosynthesis stored?
Key term
Why does reforestation act as a carbon sink?
Take On the Wild Side further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Gross primary productivity vs Net primary productivity
Gross primary productivity: total chemical energy fixed by producers. Net primary productivity: chemical energy remaining after producer respiration.
Nitrification vs Denitrification
Nitrification: oxidation of ammonium compounds into nitrites and nitrates. Denitrification: reduction of nitrates into gaseous nitrogen.
Succession vs Zonation
Succession: directional change in community composition over time. Zonation: spatial change in community composition across an environmental gradient.
Questions from this topic
Each one with the model answer underneath.
- 1
What happens to electrons in chlorophyll when light energy is absorbed during the light-dependent reactions?
Model answer
The electrons become excited (raised to a higher energy level) by the absorbed light energy.
- 2
How are excited electrons from chlorophyll used to produce ATP?
Model answer
The excited electrons pass through electron carriers, and the energy released is used to generate ATP in a process called photophosphorylation.
- 3
What molecule is formed when excited electrons from chlorophyll are used to reduce NADP?
Model answer
Reduced NADP (NADPH).
- 4
What process produces oxygen during the light-dependent reactions?
Model answer
Photolysis of water.
- 5
Besides oxygen, what other products are released by the photolysis of water?
Model answer
Electrons and protons (H⁺ ions), which are used in the light-dependent reactions.
- 6
What is the role of the products from the light-dependent reactions in the light-independent reactions?
Model answer
ATP and reduced NADP from the light-dependent reactions are used to reduce carbon dioxide in the light-independent reactions.
What is inside Levo
Six ways to work the same material.
On the Wild Side revision questions
- What does On the Wild Side cover in Edexcel A-Level Biology A?
- 21 subtopics: photosynthesis: the light-dependent reactions, photosynthesis: the calvin cycle, chloroplast structure and the products of photosynthesis, productivity: gpp, npp and energy transfer, core practicals on temperature and growth, temperature, enzymes and q10, sampling: quadrats and transects, succession, biotic and abiotic factors, niches and competition, ecosystem terms, evolution, speciation and validating evidence, evidence for climate change, climate models and their limitations, correlation, causation and scientific objectivity, the effects of climate change on organisms, human activities that raise greenhouse gas levels, the greenhouse effect, evolution and natural selection, speciation, how new scientific evidence is validated, the carbon cycle and reforestation, biofuels and sustainability. Each one has its own page with questions and model answers.
- How is On the Wild Side organised?
- By the Edexcel 9BN0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in On the Wild Side, 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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