Numbers
Edexcel A-Level Biology B 9BI0
Biological Molecules
Topic overviewMonosaccharides, disaccharides and polysaccharidesGlycosidic bonds and condensation reactionsStarch, glycogen and cellulose structureTriglycerides and phospholipidsSaturated and unsaturated fats and lipid propertiesAmino acid structure and the peptide bondPrimary, secondary, tertiary and quaternary structureFibrous and globular proteinsThe structure of DNADNA replication and gene mutationsThe structure of RNATranscription and translationEnzymes as globular proteinsFactors affecting enzyme activityMeasuring the rate of enzyme activityUnits, uncertainty and experimental errorEnzyme inhibitionInorganic ionsThe properties of water
Cells, Viruses and Reproduction of Living Things
Topic overviewCell theory and eukaryotic cell structureProkaryotic cells and Gram stainingMicroscopy, magnification and resolutionSignificant figures, estimates and mathematical symbolsVirus structure and classificationThe lytic cycle and latencyTreating viral disease and the ethics of untested drugsThe cell cycle and its regulationMitosis and the behaviour of chromosomesMitosis in growth, repair and root tip squashesMeiosis, genetic variation and chromosome mutationsGametogenesis in mammalsFertilisation and early embryo developmentPollen and embryo sac formationDouble fertilisation in flowering plantsInvestigating pollen tube growth
Classification and Biodiversity
Exchange and Transport
Topic overviewSurface area to volume ratioThe fluid mosaic modelDiffusion, osmosis and facilitated diffusionActive transport, endocytosis and exocytosisGas exchange in insects, fish and mammalsDissecting the insect gas exchange systemGas exchange in flowering plantsThe structure of the heart and blood vesselsThe double circulatory systemThe cardiac cycleMyogenic stimulation and ECG tracesThe composition of bloodThe functions of blood and clottingAtherosclerosis and its risk factorsHaemoglobin and the Bohr effectOxygen dissociation curvesFormation of tissue fluidThe lymphatic systemXylem and phloem structureApoplastic and symplastic pathwaysThe cohesion-tension theoryMeasuring transpiration with a potometerTranslocation and the mass flow hypothesis
Energy for Biological Processes
Topic overviewAn overview of aerobic respirationGlycolysisThe link reaction and the Krebs cycleThe electron transport chainChemiosmosis and ATP yieldAnaerobic respiration and ATP yieldMeasuring respiration with a respirometerAbsorption and action spectraPhotosynthetic pigments and chromatographyChloroplast structure and the light-dependent stageThe Calvin cycleLimiting factors in photosynthesis
Microbiology and Pathogens
Topic overviewCulturing microorganisms and aseptic techniqueMeasuring bacterial growthThe bacterial growth curveBacteria as pathogensThe action of antibioticsAntibiotic resistanceOther pathogenic agentsControlling endemic diseasePhagocytosis and the humoral responseThe cell-mediated immune responseMemory cells and the secondary responseNatural and artificial immunityVaccination and herd immunity
Modern Genetics
Origins of Genetic Variation
Topic overviewMutation, meiosis and random fertilisationGenotype, phenotype and monohybrid inheritanceDihybrid crosses and pedigree diagramsAutosomal linkage and sex linkageThe chi-squared test in geneticsSelection pressures and allele frequencyGenetic drift and the founder effectThe Hardy-Weinberg equation
Control Systems
Topic overviewHomeostasis and negative feedbackChemical control in mammalsPlant growth substancesAuxins, cytokinins and apical dominancePhytochrome and photomorphogenesisThe organisation of the nervous systemBrain regions and divisions of the peripheral nervous systemThe autonomic nervous systemResting potential and the action potentialPropagation and saltatory conductionSynaptic transmissionEffects of drugs on the nervous systemThe structure of the retina and rhodopsinRods, cones and visual acuityControl of heart rateKidney structure and ultrafiltrationSelective reabsorption and the loop of HenleADH and osmoregulationThermoregulation in endotherms
Ecosystems
Topic overviewEcosystems, habitats and nichesPyramids of numbers, biomass and energyEcological techniques for measuring distributionChoosing the right ecological techniquePresenting data in tables and graphsStatistical tests in ecologyProductivity and energy transfer efficiencyDecomposers and nutrient cyclingSuccessionBiotic and abiotic factors in population changeHuman influences on ecosystemsSustainability, resource management and peer review
Modern Genetics
- 8 subtopics
- 24 things to know
- Papers 1 and 3
What Modern Genetics covers
What gene sequencing makes possible, how gene expression is controlled by transcription factors and by epigenetic change, what stem cells can do, and how DNA is cut, inserted and expressed in another organism.
Where it is assessed
Papers 1 and 3
Advanced Biochemistry, Microbiology and Genetics, then the general and practical principles paper.
Check the Pearson Edexcel specification ↗The 8 subtopics
Each one has its own page.
- Using gene sequencingRecall questions on genomes, the denaturation, annealing and extension steps of PCR, how gene sequencing predicts protein structure and identifies mutations, and DNA profiling for forensics and paternity, with when to use each technique.Open →
- Transcription factors and RNA splicingRecall questions on transcription factors as activators and repressors that bind near genes and control RNA polymerase, and RNA splicing of pre-mRNA: exons, introns and how alternative splicing lets one gene code for several proteins.Open →
- Epigenetics and gene expressionRecall questions on epigenetic modification, non-coding RNA, histone acetylation and methylation, DNA methylation at CpG sites, and how accumulating epigenetic silencing restricts cells from totipotent to pluripotent to differentiated.Open →
- Stem cellsRecall questions on totipotent, pluripotent and multipotent stem cells and where they are found, the medical promise and ethical concerns of embryonic stem cells, and producing induced pluripotent stem cells from fibroblasts with transcription factors.Open →
- Producing recombinant DNARecall questions on recombinant DNA, restriction endonucleases and sticky ends, why donor and vector DNA are cut with the same enzyme, annealing of the fragments, and sealing the joins with DNA ligase.Open →
- Vectors and transformationRecall questions on vectors, viral vectors and gene guns for plant cells, antibiotic resistance marker genes, and using replica plating to identify cells that carry recombinant DNA.Open →
- Knockout mice and GM soya beansRecall questions on how knockout mice are produced and used to study gene function and disease, and why soya beans were modified to alter their balance of fatty acids and prevent oxidation.Open →
- The debate over genetically modified cropsRecall questions on the benefits claimed, the ecological and economic concerns, and the arguments on each side.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Process
How does alternative splicing allow one gene to code for multiple proteins?
Key term
Define a stem cell, and distinguish totipotent from multipotent stem cells.
Process
Explain the mechanism by which differentiated fibroblasts become pluripotent during iPS cell production.
Key term
Why are sticky ends useful in genetic engineering?
Process
Why are gene guns particularly useful for transforming plant cells, and how do gene guns deliver genetic material?
Key term
What is a genome?
Key term
What medical opportunities do pluripotent stem cells from embryos provide?
Process
What happens to epigenetic modifications as embryonic cells divide?
Key term
What are fibroblasts?
Key term
How might pests evolve in response to widespread use of pest-resistant GM crops?
Key term
What is recombinant DNA?
Key term
What is a vector in the context of gene technology?
Key term
What are knockout mice?
Key term
How do knockout mice help scientists investigate gene function?
Key term
Define transgenic organisms.
Key term
What is PCR and what is its purpose?
Key term
What are transcription factors?
Key term
What happens to introns during RNA splicing?
Key term
What is artificially introduced into fibroblasts to reprogram them into iPS cells?
Key term
Define restriction endonucleases.
Key term
How can viruses be used as vectors in gene technology?
Key term
What specific modification has been made to the composition of genetically modified soya beans?
Evaluation
State one advantage of genetic modification of crops relating to food quality.
Take Modern Genetics further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Totipotent cell vs Pluripotent cell
Totipotent cell: unspecialised cell able to form embryonic and extra-embryonic tissues. Pluripotent cell: unspecialised cell able to form every body-cell type.
Transcription vs Translation
Transcription: production of RNA from a DNA template. Translation: assembly of a polypeptide from an RNA template.
Gene therapy vs Genetic screening
Gene therapy: treatment involving introduction of a functional genetic sequence. Genetic screening: testing to identify particular genetic variants.
Questions from this topic
Each one with the model answer underneath.
- 1
What is a genome?
Model answer
The entire genetic material of an organism, comprising all of its DNA including all genes and non-coding sequences.
- 2
What is PCR and what is its purpose?
Model answer
PCR (polymerase chain reaction) is a technique used to amplify small samples of DNA to produce many copies.
- 3
What happens during the denaturation step of PCR?
Model answer
Heating to approximately 95°C separates the double-stranded DNA into two single strands.
- 4
What occurs during the annealing step of PCR and at what temperature?
Model answer
Cooling to approximately 55°C allows primers to bind to complementary sequences on the single-stranded DNA.
- 5
Describe the extension step of PCR.
Model answer
Heating to approximately 72°C allows DNA polymerase to synthesise new complementary DNA strands using the primers as starting points.
- 6
Why is the temperature raised to 72°C during the extension phase of PCR?
Model answer
This is the optimum temperature for DNA polymerase (typically Taq polymerase) to synthesise new DNA strands.
What is inside Levo
Six ways to work the same material.
Modern Genetics revision questions
- What does Modern Genetics cover in Edexcel A-Level Biology B?
- 8 subtopics: using gene sequencing, transcription factors and rna splicing, epigenetics and gene expression, stem cells, producing recombinant dna, vectors and transformation, knockout mice and gm soya beans and the debate over genetically modified crops. Each one has its own page with questions and model answers.
- How is Modern Genetics organised?
- By the Edexcel 9BI0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Modern Genetics, 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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