Book a tutor
SearchResourcesRevision notesFlashcardsMind mapsExam questionsTopic testsPracticalsGCSE Biology coursesAQA GCSE Biology (8461)AQA GCSE Combined Science: Trilogy (8464)Edexcel GCSE Biology (1BI0)Edexcel GCSE Combined Science (1SC0)IGCSE Biology coursesCambridge IGCSE Biology (0610)Cambridge IGCSE Combined Science (0653)Edexcel International GCSE Biology (4BI1)Edexcel International GCSE Science (Double Award) (4SD0)IB Diploma Biology coursesIB Diploma Biology SLIB Diploma Biology HLA-level Biology coursesEdexcel International A Level Biology (YBI11)Edexcel International AS Level Biology (XBI11)MoreBlogVideosAboutContact
Book a tutor

Edexcel International A Level Biology revision notes

Short notes for every spec point. Pick a topic, then a note.

1

Molecules, Transport and Health

4 subtopics · 24 notes

Water, carbohydrates and lipids
  1. Subtopic overview: questions, flashcards and PDFs
  2. Water as a solvent in transport
  3. Monosaccharides, disaccharides and polysaccharides
  4. Glycosidic bonds: condensation and hydrolysis
  5. Core practical 1: Benedict’s reagent and iodine solution
  6. Triglycerides and ester bonds
  7. Saturated and unsaturated lipids
The heart, blood vessels and haemoglobin
  1. Subtopic overview: questions, flashcards and PDFs
  2. Why many animals have a heart and circulation
  3. Arteries, veins and capillaries
  4. Structure of the mammalian heart
  5. The cardiac cycle
  6. Haemoglobin and the transport of oxygen and carbon dioxide
  7. The oxygen dissociation curve, the Bohr effect and fetal haemoglobin
Cardiovascular disease and its causes
  1. Subtopic overview: questions, flashcards and PDFs
  2. Atherosclerosis
  3. Blood clotting and cardiovascular disease
  4. Risk factors for cardiovascular disease
  5. Dietary antioxidants and the risk of CVD
  6. Core practical 2: vitamin C content of food and drink
Health risks, evidence and treatment
  1. Subtopic overview: questions, flashcards and PDFs
  2. Analysing data on illness and mortality
  3. Evaluating the design of studies
  4. Perception of risk
  5. Blood cholesterol, HDL and LDL
  6. Evidence linking cholesterol and CVD
  7. Using scientific knowledge to reduce the risk of CHD
  8. Treatments for cardiovascular disease
All molecules, transport and health notes (PDF)Download all notes (PDF)28 pages
2

Membranes, Proteins, DNA and Gene Expression

4 subtopics · 27 notes

Gas exchange, membranes and transport
  1. Subtopic overview: questions, flashcards and PDFs
  2. Gas exchange surfaces and Fick's law
  3. The mammalian lung
  4. The structure and properties of cell membranes
  5. Models of membrane structure and the evidence for them
  6. Core practical 3: membrane permeability, alcohol and temperature
  7. Osmosis and water potential
  8. Passive transport: diffusion, facilitated diffusion, channel and carrier proteins
  9. Active transport, endocytosis and exocytosis
Proteins and enzymes
  1. Subtopic overview: questions, flashcards and PDFs
  2. Amino acids, peptide bonds and polypeptides
  3. Levels of protein structure and the bonds involved
  4. Globular and fibrous proteins: haemoglobin and collagen
  5. Enzymes: mode of action and specificity
  6. Factors affecting the rate of enzyme-catalysed reactions
  7. Core practical 4: the initial rate of enzyme-catalysed reactions
DNA, the genetic code and gene expression
  1. Subtopic overview: questions, flashcards and PDFs
  2. The structure of mononucleotides, DNA and RNA
  3. DNA replication and the role of DNA polymerase
  4. The Meselson–Stahl experiment
  5. The genetic code and the gene
  6. Transcription
  7. Translation, tRNA and ribosomes
  8. Gene mutations
Inheritance, cystic fibrosis and genetic screening
  1. Subtopic overview: questions, flashcards and PDFs
  2. Genetic terms
  3. Monohybrid inheritance and pedigree diagrams
  4. Sex linkage and red-green colour blindness
  5. Cystic fibrosis
  6. Genetic screening: carriers, PGD and prenatal testing
  7. Ethical and social issues of genetic screening
All membranes, proteins, dna and gene expression notes (PDF)Download all notes (PDF)42 pages
3

Cell Structure, Reproduction and Development

5 subtopics · 23 notes

Cells, tissues and organelles
  1. Subtopic overview: questions, flashcards and PDFs
  2. Features common to all living cells
  3. Tissues, organs and organ systems
  4. Ultrastructure of eukaryotic cells
  5. Protein transport and extracellular enzymes
  6. Ultrastructure of prokaryotic cells
  7. Recognising organelles in electron micrographs
Microscopy and measuring cells
  1. Subtopic overview: questions, flashcards and PDFs
  2. Magnification and resolution
  3. Staining specimens
  4. Core Practical 5: observing, drawing and measuring cells
Chromosomes, meiosis and gametes
  1. Subtopic overview: questions, flashcards and PDFs
  2. Gene loci and linkage
  3. Meiosis and genetic variation
  4. Specialised mammalian gametes
  5. Fertilisation in mammals
  6. Fertilisation in flowering plants
Mitosis and the cell cycle
  1. Subtopic overview: questions, flashcards and PDFs
  2. The cell cycle and mitosis
  3. Core Practical 6: root tip squash
  4. Calculating the mitotic index
Stem cells, gene expression and phenotype
  1. Subtopic overview: questions, flashcards and PDFs
  2. Stem cells and potency
  3. Using stem cells in medical therapies
  4. Differential gene expression and specialisation
  5. One gene, more than one protein
  6. Genotype, environment and epigenetics
  7. Multiple alleles, polygenic inheritance and variation
All cell structure, reproduction and development notes (PDF)Download all notes (PDF)28 pages
4

Plant Structure and Function, Biodiversity and Conservation

5 subtopics · 20 notes

Plant cells and cell walls
  1. Subtopic overview: questions, flashcards and PDFs
  2. Plant cell ultrastructure and its functions
  3. Starch and cellulose
  4. Cell wall structure, secondary thickening and plant fibres
Plant tissues, fibres and mineral nutrition
  1. Subtopic overview: questions, flashcards and PDFs
  2. Sclerenchyma fibres, xylem vessels and phloem
  3. Core practical 7: plant tissues under the light microscope
  4. Plant fibres, starch and sustainability
  5. Water and inorganic ions in plants
  6. Core practical 8: tensile strength of plant fibres
Bacterial growth, plant medicines and drug testing
  1. Subtopic overview: questions, flashcards and PDFs
  2. Conditions required for bacterial growth
  3. Antimicrobial and therapeutic substances from plants
  4. Core practical 9: antimicrobial properties of plants and aseptic technique
  5. The development of drug testing
Classification and biodiversity
  1. Subtopic overview: questions, flashcards and PDFs
  2. Classification and the three-domain system
  3. Biodiversity, endemism and human threats
  4. Measuring biodiversity: species richness and heterozygosity index
  5. Comparing habitats: index of diversity (D)
Niche, allele frequency and conservation
  1. Subtopic overview: questions, flashcards and PDFs
  2. Niche and adaptations to the environment
  3. The Hardy-Weinberg equation, mutation and natural selection
  4. Reproductive isolation and the formation of new species
  5. Evaluating zoos and seed banks in conservation
All plant structure and function, biodiversity and conservation notes (PDF)Download all notes (PDF)32 pages
5

Energy Flow, Ecosystems and the Environment

4 subtopics · 23 notes

PhotosynthesisA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. The overall reaction and the role of ATP
  3. The light-dependent reactions
  4. The light-independent reactions (Calvin cycle)
  5. Chloroplast structure and function
  6. Pigments, spectra and chromatography
  7. Core practical 10: factors affecting the rate of photosynthesis
Productivity and ecosystemsA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Gross and net primary productivity
  3. Efficiency of biomass and energy transfers
  4. Population, community, habitat and ecosystem; biotic and abiotic factors
  5. The concept of niche
  6. Core practical 11: a study of the ecology of a habitat
  7. Succession
Climate changeA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Evidence for climate change
  3. Causes of anthropogenic climate change and the greenhouse effect
  4. The carbon cycle and reducing atmospheric carbon dioxide
  5. Predicting climate change: extrapolation and models
  6. Effects of climate change on plants and animals
  7. Evaluating scientific conclusions on controversial issues
  8. Reforestation, sustainable resources and biofuels
Temperature, evolution and speciationA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Temperature, enzyme activity and Q₁₀
  3. Core practical 12: temperature and the development of organisms
  4. Evolution: mutation and natural selection
  5. Isolation and speciation
All energy flow, ecosystems and the environment notes (PDF)Download all notes (PDF)33 pages
6

Microbiology, Immunity and Forensics

5 subtopics · 21 notes

Culturing and measuring microorganismsA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Culturing microorganisms using aseptic technique
  3. Measuring the growth of microorganisms
  4. The bacterial growth curve and growth rate constants
  5. Core practical 13: rate of growth in liquid culture
Bacteria, viruses and infectionA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Structure of bacteria and viruses
  3. The terms lytic and latency
  4. How Mycobacterium tuberculosis and HIV cause disease
  5. Routes of entry and protective barriers
The immune responseA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Non-specific responses to infection
  3. Antigens, antibodies and antigen-presenting cells
  4. B cells and T cells in the immune response
  5. Natural, artificial, active and passive immunity
  6. The evolutionary race between pathogens and hosts
Antibiotics and infection controlA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Bacteriostatic and bactericidal antibiotics
  3. Core practical 14: effect of antibiotics on bacteria
  4. Hospital-acquired infections and codes of practice
Decay, DNA techniques and forensicsA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Microorganisms, decomposition and recycling carbon
  3. Amplifying DNA by the polymerase chain reaction
  4. Separating DNA fragments by gel electrophoresis
  5. DNA profiling
  6. Estimating time of death
All microbiology, immunity and forensics notes (PDF)Download all notes (PDF)33 pages
7

Respiration, Muscles and the Internal Environment

5 subtopics · 24 notes

Stages of respirationA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Aerobic respiration: the overall reaction
  3. Glycolysis
  4. The link reaction and the Krebs cycle
  5. Oxidative phosphorylation
  6. Anaerobic respiration and lactate
Respiratory quotient and respiration practicalsA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Respiratory quotient (RQ)
  3. Core practical 15: redox indicator and yeast
  4. Core practical 16: respirometer and RQ
Muscles and movementA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Muscles, tendons, the skeleton and ligaments
  3. Structure of a skeletal muscle fibre
  4. Fast and slow twitch muscle fibres
  5. Contraction and the sliding filament theory
The heart, ventilation and exerciseA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Cardiac muscle and the coordination of the heartbeat
  3. Electrocardiograms (ECGs)
  4. Cardiac output and the control of heart rate and ventilation
  5. Adrenaline and the fight or flight response
  6. Core practical 17: exercise and spirometer traces
Homeostasis, hormones and the kidneyA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Negative and positive feedback
  3. Homeostasis and thermoregulation
  4. Hormones and transcription factors
  5. Structure of the mammalian kidney
  6. Urea production and ultrafiltration
  7. Selective reabsorption and the loop of Henle
  8. ADH and the control of plasma concentration
All respiration, muscles and the internal environment notes (PDF)Download all notes (PDF)32 pages
8

Coordination, Response and Gene Technology

5 subtopics · 23 notes

Neurones, reflexes and the nervous systemA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Sensory, relay and motor neurones
  3. The nervous system and its effectors
  4. The spinal reflex arc
Impulses, synapses and receptorsA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Resting potential and action potentials
  3. Myelination and saltatory conduction
  4. Synapses and neurotransmitters
  5. How the pupil dilates and constricts
  6. Drugs and nerve impulse transmission
  7. Rods, rhodopsin and the optic neurone
  8. Habituation
Plant responsesA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Phytochrome
  3. Auxin (IAA)
  4. Gibberellins
  5. Core practical 18: amylase in germinating cereal grains
The brain and hormonal controlA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Nervous and hormonal coordination
  3. Regions of the human brain
  4. Imaging the brain: CT, MRI, fMRI and PET
  5. Brain chemicals and ill health
Gene technologyA Level only
  1. Subtopic overview: questions, flashcards and PDFs
  2. Making recombinant DNA
  3. Inserting recombinant DNA into cells
  4. Drugs from genetically modified organisms
  5. Microarrays and bioinformatics
  6. Risks and benefits of GMOs
All coordination, response and gene technology notes (PDF)Download all notes (PDF)26 pages