Key term
CCEA A-Level Biology 1010
Biological Molecules
Topic overviewWater as a solventInorganic ions and their rolesMonosaccharides and the glycosidic bondDisaccharides and polysaccharidesLipids, triglycerides and phospholipidsAmino acids and protein structureProtein shape, conjugated proteins and prionsNucleic acids: nucleotides, DNA and RNADNA replication and the Meselson–Stahl experimentBiochemical tests and paper chromatography
Enzymes
Topic overviewEnzymes as globular proteins and the active siteSpecificity, cofactors and coenzymesActivation energy and models of enzyme actionThe effect of temperature and pHThe effect of substrate and enzyme concentrationCompetitive and non-competitive inhibitionEnzymes as biomarkers of disease and inhibitors as drugsImmobilised enzymes and biosensors
Viruses and Cell Structure
Topic overviewBacteriophage and HIV structureViral replication in host cellsProkaryotic and eukaryotic cells comparedMembrane structure: the fluid mosaic modelFunctions of membrane componentsMitochondria and chloroplastsRibosomes, endoplasmic reticulum, Golgi apparatus and lysosomesThe nucleus, the cytoskeleton and plasmodesmataPlant, fungal and animal cellsMicroscopy, cell measurement and cell fractionation
Cell Physiology and Transport
Continuity of Cells
Topic overviewThe cell cycle: interphase and the gap phasesControl points in the cell cycle and cancerChromosome structure, haploidy and diploidyMitosis: the events of the four stagesCytokinesis and the significance of mitosisAnticancer drugs and the cell cycleMeiosis I and the first divisionMeiosis II and the significance of meiosisPreparing and examining slides of cell division
Tissues and Organs
Exchange Surfaces and Gas Exchange
Topic overviewSurface area, volume and the surface area to volume ratioFeatures of efficient exchange surfacesThe need for mass transport systemsFick's law and the rate of gas exchangeGas exchange in plants and the compensation pointGas exchange at the alveolusThe respiratory tree and the mechanism of ventilationThe effects of smoking on the breathing systemUsing a respirometer to measure gas exchange
Transport in Plants
Topic overviewEpidermis, endodermis and the tissues of the rootXylem vessels and their lignification patternsPhloem: sieve-tube elements and companion cellsWater and mineral ion uptake by root hairsThe apoplast and symplast pathwaysTranspiration and the factors affecting its rateCohesion-tension theory and the transpiration streamTranslocation of organic solutes in the phloemXerophytes and hydrophytes
The Circulatory System in Mammals
Topic overviewDouble circulation and the major blood vesselsThe structure and function of arteries, veins and capillariesAtherosclerosis, atheroma and the investigation of blood vesselsThe structure of the mammalian heartThe cardiac cycle and the operation of the valvesMyogenic stimulation and the electrocardiogramBlood cells and the stained blood filmPlasma, tissue fluid and blood clottingHaemoglobin and the oxygen dissociation curveThe Bohr effect, myoglobin and altitude
Adaptation and Biodiversity
Topic overviewAdaptation and the ways organisms meet environmental challengesEcological factors and the ecological nicheSampling procedures and sampling devicesEstimating abundance, density, frequency and percentage coverThe biochemical basis of life and the levels of biodiversityMeasuring species diversity with Simpson's indexHandling data: averages, spread and the t-testTaxonomy, nomenclature and the binomial systemThe concept of a speciesThe taxonomic hierarchy from genus to kingdomPhylogenetic taxonomy and molecular evidenceThe five kingdom system: prokaryotae, protoctista and fungiPlantae, animalia and alternative classification systems
Human Impact on Biodiversity
Topic overviewMonoculture, polyculture and intensive agricultureCrop rotation and hedgerow conservationPredator strips, pesticides and integrated pest managementOrganic pollution of waterways by slurry and silage effluentEutrophication and fertiliser run-offBiological oxygen demand and reducing aquatic pollutionConservation initiatives and habitat protectionGlobal warming, climate change and biodiversity
Homeostasis and Excretion
Topic overviewPrinciples of homeostasis and negative feedbackExcretion, osmoregulation and nitrogenous wasteGross structure of the kidney and the urinary systemStructure of the nephron and its blood supplyEpithelia of the nephron and their adaptationsThe glomerular filterUltrafiltration and the forces that drive itSelective reabsorption in the proximal convoluted tubuleThe loop of Henlé and the medullary salt gradientADH, osmoreceptors and the control of water balance
Immunity
Topic overviewNatural barriers to infectionAntigens, antibodies and the antigen–antibody reactionAntibody-mediated immunity and B-lymphocytesCell-mediated immunity and T-lymphocytesActive immunity, passive immunity and vaccinationTransplant rejection and immunosuppressionBlood group polymorphism and the rhesus factorTransfusion compatibility and its consequencesAntibiotic resistance and the search for new antimicrobialsELISA and the detection of disease biomarkers
Co-Ordination and Control
Topic overviewPhytochromes and the control of floweringPlant growth substances and stem elongationThe structure of a neuroneResting potential, threshold and the action potentialImpulse propagation and the speed of conductionSynapse structure and chemical transmissionExcitatory and inhibitory post-synaptic potentialsGross structure of the eye and accommodationThe retina, rods and conesSkeletal muscle and the sliding filament theory
Populations and Communities
Topic overviewPopulation growth curves, carrying capacity and environmental resistancer-selected and K-selected speciesInteractions between populationsBiological control of pest speciesPopulation dynamics and changes in population sizeEstimating population size in the field and the laboratoryCommunities and ecosystemsSuccession and climax communities
Ecological Energetics and Nutrient Cycling
Topic overviewFood chains, food webs and detritus food chainsTrophic levels, gross and net primary productionEcological pyramids and their usefulnessEnergy transfer efficiency between trophic levelsWhy energy is lost at each trophic levelImplications for agriculture and intensive farmingThe carbon cycleThe nitrogen cycle and the role of bacteria
Respiration
Topic overviewATP and the ATP/ADP cycleGlycolysisThe mitochondrion and the sites of aerobic respirationThe link reaction and the Krebs cycleThe electron transport chain and oxidative phosphorylationATP yield from one molecule of glucoseAnaerobic respiration in animals, plants and fungiAerobic and anaerobic respiration compared, and oxygen debtRespiratory quotient and measuring respiration
Photosynthesis
Topic overviewChloroplast structure and the sites of photosynthesisPhotosynthetic pigments and paper chromatographyAbsorption spectra and action spectraPhotosystems, photoactivation and the Z-schemePhotolysis of water, reduced NADP and redox indicatorsCarbon dioxide fixation and rubiscoReduction of glycerate phosphate and regeneration of ribulose bisphosphateLimiting factors, the compensation point and measuring photosynthesis
DNA as the Genetic Code
Topic overviewGenes and the nature of the genetic codeExons, introns and RNA splicingComparing DNA and RNATranscription and RNA polymeraseTransfer RNA, ribosomes and the sites of translationTranslation and polypeptide synthesisOne gene, one polypeptide and the control of the phenotypeEpigenetics, methylation and histone modification
Gene Technology
Topic overviewThe polymerase chain reactionDNA probes and genetic markersMicroarrays, pharmacogenetics and personalised medicineGenetic fingerprinting and gel electrophoresisThe stages of gene transferGenetically modified microorganismsTransgenic animals and plantsGene therapyGenome sequencing and the Human Genome ProjectGene inactivation and knockout organismsSocial, ethical and ecological issues of gene technology
Genes and Patterns of Inheritance
Topic overviewGenotype, phenotype and the environmentChromosomes, genes and allelesMonohybrid inheritance and Mendel's first lawCodominance, multiple alleles and lethal allelesTest crossesDihybrid inheritance and Mendel's second lawAutosomes, sex chromosomes and sex determinationGene interaction and epistasisPolygenic inheritance and continuous variationThe chi-squared test
Population Genetics and Evolution
Evolutionary Trends in Plants
Ecological Energetics and Nutrient Cycling
- 8 subtopics
- 24 things to know
- Unit A2 1
What Ecological Energetics and Nutrient Cycling covers
Ecological Energetics and Nutrient Cycling is examined in Unit A2 1, Physiology, Co-ordination and Control, and Ecosystems, and drawn on again in Unit A2 3, the practical skills examination. It covers food chains, food webs and detritus food chains, trophic levels, gross and net primary production, ecological pyramids and their usefulness, energy transfer efficiency between trophic levels, why energy is lost at each trophic level, Implications for agriculture and intensive farming, the carbon cycle and the nitrogen cycle and the role of bacteria.
Where it is assessed
Unit A2 1
Physiology, Co-ordination and Control, and Ecosystems, and again in Unit A2 3, Practical Skills in Biology.
Check the CCEA specification ↗The 8 subtopics
Each one has its own page.
- Food chains, food webs and detritus food chainsFood chain, herbivore and a carnivore and food web.Open →
- Trophic levels, gross and net primary productionTrophic level, trophic position of an animal that eats a herbivore and gross primary production.Open →
- Ecological pyramids and their usefulnessEcological pyramid, measured in a pyramid of numbers and how a pyramid of numbers can become inverted.Open →
- Energy transfer efficiency between trophic levelsRecall questions on calculating efficiency from figures for each level, why the transfer is only a small percentage, why the herbivore step is usually the least efficient, and what the efficiency implies for the length of a food chain.Open →
- Why energy is lost at each trophic levelRecall questions on the material never eaten, the material eaten but not absorbed, and the energy respired and lost as heat, together with the implications for how much of the sun's energy reaches a top carnivore.Open →
- Implications for agriculture and intensive farmingExtra energy cost of producing animal products, one argument in favour of keeping livestock on some farmland and two economic advantages of intensive farming.Open →
- The carbon cycleThree processes that add carbon dioxide to the atmosphere, role of decomposition in the carbon cycle and combustion in the context of the carbon cycle.Open →
- The nitrogen cycle and the role of bacteriaRecall questions on nitrogen fixation, ammonification, nitrification and denitrification and the bacteria responsible for each, the aerobic and anaerobic conditions each requires, and why nitrate matters to protein and nucleic acid synthesis.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Evaluation
State one argument in favour of keeping livestock on some farmland.
Key term
Why does draining and ploughing a field improve its supply of nitrate?
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What is a producer?
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What is a trophic level?
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What is measured in a pyramid of numbers?
Process
Name the process by which most energy is lost from a trophic level as heat.
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In what form is most of the carbon of the atmosphere found?
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What is a consumer?
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Which organisms occupy the first trophic level?
Evaluation
Give one advantage of a pyramid of numbers.
Key term
State how the efficiency of transfer between two trophic levels is calculated.
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Why can heat energy not be passed to the next trophic level?
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Why does producing a kilogram of beef need far more land than producing a kilogram of wheat?
Process
Which process removes carbon dioxide from the atmospheric pool?
Key term
Why does a plant need a supply of nitrogen?
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Distinguish between a herbivore and a carnivore.
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Name the trophic position of an animal that eats a herbivore.
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Explain how a pyramid of numbers can become inverted.
Numbers
Producers store 20 000 kJ m⁻² yr⁻¹ and the primary consumers store 1 600 kJ m⁻² yr⁻¹. Calculate the efficiency of transfer between them.
Key term
What is egestion?
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How do fertilisers raise the primary productivity of a crop?
Process
Name three processes that add carbon dioxide to the atmosphere.
Key term
In which form do plants take up nitrogen from the soil?
Take Ecological Energetics and Nutrient Cycling further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
What is a food chain?
Model answer
A food chain is a sequence of organisms in which each is eaten by the next, showing the route by which energy passes through a community.
- 2
What does an arrow in a food chain represent?
Model answer
An arrow points from the organism that is eaten to the organism that eats it, and shows the direction in which energy and biomass flow.
- 3
What is a producer?
Model answer
A producer is an autotroph, usually a green plant, that converts light energy into chemical energy held in organic compounds.
- 4
What is a consumer?
Model answer
A consumer is a heterotroph that obtains its energy by eating other organisms.
- 5
Distinguish between a herbivore and a carnivore.
Model answer
A herbivore feeds on plant material, whereas a carnivore feeds on other animals.
- 6
What is a food web?
Model answer
A food web is a set of interconnected food chains that shows all the feeding relationships within a community.
What is inside Levo
Six ways to work the same material.
Ecological Energetics and Nutrient Cycling revision questions
- What does Ecological Energetics and Nutrient Cycling cover in CCEA A-Level Biology?
- 8 subtopics: food chains, food webs and detritus food chains, trophic levels, gross and net primary production, ecological pyramids and their usefulness, energy transfer efficiency between trophic levels, why energy is lost at each trophic level, implications for agriculture and intensive farming, the carbon cycle and the nitrogen cycle and the role of bacteria. Each one has its own page with questions and model answers.
- How is Ecological Energetics and Nutrient Cycling organised?
- By the CCEA 1010 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Ecological Energetics and Nutrient Cycling, 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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