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
Immunity
- 10 subtopics
- 30 things to know
- Unit A2 1
What Immunity covers
Immunity 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 natural barriers to infection, antigens, antibodies and the antigen–antibody reaction, antibody-mediated immunity and B-lymphocytes, cell-mediated immunity and T-lymphocytes, active immunity, passive immunity and vaccination, transplant rejection and immunosuppression, blood group polymorphism and the rhesus factor, transfusion compatibility and its consequences, antibiotic resistance and the search for new antimicrobials and ELISA and the detection of disease biomarkers.
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 10 subtopics
Each one has its own page.
- Natural barriers to infectionNatural barrier to infection, two secretions other than tears that contain lysozyme and how mucus protects the airways from infection.Open →
- Antigens, antibodies and the antigen–antibody reactionTerm antigen, term antibody and difference between self antigens and non-self antigens.Open →
- Antibody-mediated immunity and B-lymphocytesAntibody-mediated immunity, two kinds of cell produced when a B-lymphocyte divides and function of a plasma cell.Open →
- Cell-mediated immunity and T-lymphocytesCell-mediated immunity, three kinds of antigen that sensitise T-lymphocytes and four types of T-cell formed when sensitised T-lymphocytes divide.Open →
- Active immunity, passive immunity and vaccinationActive immunity and passive immunity.Open →
- Transplant rejection and immunosuppressionTransplant rejection, tissue typing and two ways in which the immune response can be suppressed.Open →
- Blood group polymorphism and the rhesus factorFour blood groups recognised in the ABO system, rhesus antigen and important difference between anti-rhesus antibodies and the ABO antibodies.Open →
- Transfusion compatibility and its consequencesTwo consequences for a patient of an incompatible transfusion and how a blood group is determined in the laboratory.Open →
- Antibiotic resistance and the search for new antimicrobialsEpidemic and a pandemic, animal reservoir of a pathogen and purpose of preparing a streak plate.Open →
- ELISA and the detection of disease biomarkersRecall questions on the antibody bound to the well, the antigen it captures, the second enzyme-linked antibody, the colour change and what it shows, the washing steps and why they matter, and what a negative result means.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Why is antibody-mediated immunity described as specific?
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Describe how the antimicrobial activity of a plant extract could be compared with that of an antibiotic.
Process
Outline the main steps of an ELISA used to detect a protein in a blood sample.
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What is meant by a natural barrier to infection?
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What is cell-mediated immunity?
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Define active immunity.
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What is transplant rejection?
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What determines a person's blood group?
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What must be compared in order to decide whether a transfusion is safe?
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How does intact skin act as a barrier to infection?
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Define the term antigen.
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Which lymphocytes carry out antibody-mediated immunity?
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Name three kinds of antigen that sensitise T-lymphocytes.
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Define passive immunity.
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Why does a recipient's immune system attack a transplant?
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Name the four blood groups recognised in the ABO system.
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Why are the antibodies in donated blood not usually a problem for the recipient?
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What is an antibiotic?
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What do the letters ELISA stand for?
Process
Which enzyme in tears attacks bacteria, and how does it work?
Key term
Where on a bacterium would you expect its antigens to be found?
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What triggers one particular B-lymphocyte, rather than any other, to divide?
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What happens to a T-lymphocyte once it has been sensitised?
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Name the two natural routes by which a baby gains passive immunity.
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Which cells attack the transplanted tissue?
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Which antigens are carried on the red cells of a person of group AB?
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Which ABO group can receive red cells from a donor of any ABO group, and why?
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How does antibiotic resistance arise in a population of bacteria?
Process
Why is each well washed between the steps of an ELISA?
Take Immunity further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by a natural barrier to infection?
Model answer
A natural barrier is a physical or chemical feature of the body that stops pathogens entering, before any specific immune response is needed.
- 2
How does intact skin act as a barrier to infection?
Model answer
The tough outer layer of dead, keratinised cells forms a continuous physical barrier that most pathogens cannot penetrate.
- 3
Which enzyme in tears attacks bacteria, and how does it work?
Model answer
Lysozyme in tears digests the cell walls of bacteria, so the cells burst.
- 4
Name two secretions other than tears that contain lysozyme.
Model answer
Saliva and nasal mucus also contain lysozyme.
- 5
How does the acid in the stomach protect against infection?
Model answer
Hydrochloric acid gives the stomach contents a very low pH, which denatures the enzymes of swallowed bacteria and kills them.
- 6
Explain how mucus protects the airways from infection.
Model answer
Sticky mucus traps pathogens and dust particles, and cilia sweep the loaded mucus up to the throat where it is swallowed.
What is inside Levo
Six ways to work the same material.
Immunity revision questions
- What does Immunity cover in CCEA A-Level Biology?
- 10 subtopics: natural barriers to infection, antigens, antibodies and the antigen–antibody reaction, antibody-mediated immunity and b-lymphocytes, cell-mediated immunity and t-lymphocytes, active immunity, passive immunity and vaccination, transplant rejection and immunosuppression, blood group polymorphism and the rhesus factor, transfusion compatibility and its consequences, antibiotic resistance and the search for new antimicrobials and elisa and the detection of disease biomarkers. Each one has its own page with questions and model answers.
- How is Immunity organised?
- By the CCEA 1010 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Immunity, 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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