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Module 1: Development of practical skills in biology
1.1 Practical skills assessed in a written examination
1.1.1(a)-(c) - Planning experimental design and controlled variablesIn this lesson you are learning how to turn a biological question into a practical method that can actually answer it. The skill is not just naming variables; it is choosing apparatus, techniques and controls so the results could meet the expected outcome. OCR often tests this by giving you a pra...
1.1.2(a)-(c) - Implementing practical work, units and recording dataGood biology practical work is not just "doing the experiment". It means using apparatus correctly, recording each measurement with a suitable unit, and presenting observations so another scientist can understand what happened. In this lesson, you will learn the implementation habits OCR can test...
1.1.3(a)-(d)(ii) - Analysis, mathematical handling and graph skillsIn this lesson you learn how experimental results become biological conclusions. You will process qualitative and quantitative results, choose suitable mathematical handling, use significant figures sensibly, and construct or interpret graphs with correct axes, scales, units, gradients and interc...
1.1.4(a)-(e) - Evaluation, uncertainty and method improvementThis lesson is about judging the quality of practical evidence. You will learn how to move from results to a supported conclusion, how to spot anomalies and limitations, how precision, accuracy and uncertainty affect confidence, and how to suggest method improvements that are specific enough to e...
1.2 Practical skills assessed in the practical endorsement
1.2.1(a)-(c) - Investigative approaches, risk and written instructionsThis lesson is about practical competence: how to move from a biological question to a safe, workable method, and how to carry it out without losing control of the investigation. You will learn how to apply investigative approaches, solve practical problems, use equipment and materials safely, id...
1.2.1(d)-(g) - Recording, presenting and processing practical dataGood practical work is not only about doing the experiment. It is also about leaving a record that another scientist can understand, check and use as evidence. In this lesson you will learn how to make and record observations and measurements, keep appropriate practical records, present data scie...
1.2.1(h)-(j) - Research, citation and selecting practical equipmentIn practical biology, good planning begins before anyone picks up a pipette. You need to find information from suitable sources, record where it came from, and use it to choose equipment and techniques that fit the biological question. This lesson teaches those Module 1 skills as practical decisi...
1.2.2(a)-(c) - Measurement apparatus and serial dilutionsPractical biology only becomes evidence when measurements are made with apparatus that suits the question. In this lesson you will learn how to choose apparatus for quantitative measurements, how to make those measurements trustworthy, and how instruments such as colorimeters and potometers turn...
1.2.2(d)-(e) - Light microscopy and scientific biological drawingsThis lesson teaches the practical skill behind many later OCR Biology observations: using a light microscope at low and high power, measuring with a graticule, and turning observations into a clear scientific drawing. The aim is not to memorise one specimen. It is to make the microscope view reli...
1.2.2(f)-(g), 1.2.2(i) - Qualitative testing, separation and microbiologyIn this lesson you are learning three laboratory technique families that OCR expects you to use safely and explain precisely: qualitative tests for biological molecules, separation methods, and aseptic microbiology. The biology is not just the name of a test; it is the link between a method step,...
1.2.2(h), 1.2.2(j)-(l) - Responses, dissection, fieldwork and ICTIn this lesson you are learning how to choose and carry out four broad practical technique families: measuring responses in organisms, dissecting organs safely, sampling in the field, and using ICT to collect or process data. The focus is not detailed physiology, ecology or anatomy; it is the pra...
Module 2: Foundations in biology
2.1.1 Cell structure
2.1.1(a) - Microscopy to observe eukaryotic cellsThis lesson is about using microscopy as evidence: choosing a microscope because of the kind of cell structure you need to investigate, then interpreting what its image can and cannot show. The focus is eukaryotic organisms, so examples may come from animal, plant, fungal or protist cells. You ar...
2.1.1(b)-(d) - Light microscope slide preparation, staining and drawingsThis lesson teaches how a microscope observation becomes reliable evidence: prepare a thin slide, use stains sensibly, measure with calibrated scale, then communicate only what is visible. The focus is practical microscopy, not electron microscopy or organelle ultrastructure.
2.1.1(e)-(f) - Magnification, resolution and microscope comparisonsThis lesson separates two ideas students often merge: magnification makes an image bigger, while resolution makes close structures distinguishable. You will also practise the magnification formula and choose between light, transmission electron and scanning electron microscopes from evidence.
2.1.1(g)-(h) - Eukaryotic cell ultrastructure and photomicrographsThis lesson builds a usable map of eukaryotic cell components and then shows how to interpret electron micrographs without guessing. The key habit is structure-function reasoning: identify what is visible, then connect it to a precise function.
2.1.1(i)-(j) - Protein secretion organelles and the cytoskeletonThis lesson is about how eukaryotic cells coordinate internal structures to get useful proteins out of the cell and to move materials within the cell. You need the organelle sequence for protein secretion and the three key roles of the cytoskeleton: mechanical strength, intracellular transport an...
2.1.1(k) - Prokaryotic and eukaryotic cell comparisonThis lesson is about comparing two basic kinds of cellular organisation. You are not learning every organelle again; you are learning the precise structural features that let a biologist distinguish a prokaryotic cell from a eukaryotic cell. The row also links to microscopy, so the lesson include...
2.1.2 Biological molecules
2.1.2(a) - Water, hydrogen bonding and biological rolesIn this lesson you are learning why water is not just a background liquid in Biology. OCR wants you to explain how hydrogen bonding occurs between water molecules and then link water's properties to roles in living organisms. The route is molecule first, then property, then biological role, with...
2.1.2(b)-(c) - Monomers, polymers, condensation, hydrolysis and biological elementsLiving cells contain large biological molecules, but those molecules are built from a small set of recurring chemical ideas. In this lesson you learn how smaller units can join to form larger molecules, why condensation and hydrolysis reactions matter, and which chemical elements OCR expects you...
2.1.2(d)-(e) - Monosaccharides, disaccharides and glycosidic bondsThis lesson teaches carbohydrate structure at the level needed for glucose, ribose, named disaccharides and glycosidic bonds. The aim is to connect molecular shape to bond formation without drifting into later starch, cellulose or biochemical test lessons.
2.1.2(f)-(g) - Starch, glycogen and cellulose structure-functionThis lesson is about how a small difference in glucose bonding changes the job of a carbohydrate. Starch, glycogen and cellulose are all polysaccharides made from glucose, but they are not interchangeable: their linkage pattern and branching decide whether they are useful for storage or support....
2.1.2(h)-(i) - Triglycerides, phospholipids and ester bondsIn this lesson you are learning how triglycerides and phospholipids are built from glycerol and fatty acids. The key specification idea is structural: where the fatty acid chains attach, what saturated and unsaturated means, and how ester bonds form and break in triglycerides. Keep the boundary t...
2.1.2(j) - Lipid properties, cholesterol and biological functionsIn this lesson you are learning how three lipid types do their jobs because of their properties: triglycerides, phospholipids and cholesterol. The important move is not just naming a lipid, but linking a property such as hydrophobicity, amphipathic structure or high energy content to a function i...
2.1.2(k)-(m) - Amino acids, peptide bonds and protein structureThis lesson builds proteins from the bottom up: amino acid template, peptide bond, polypeptide, then four levels of protein structure. The emphasis is using precise bond language, because peptide bonds are not the same as the interactions that stabilise folding.
2.1.2(n)-(o) - Globular and fibrous proteinsThis lesson is about how protein shape fits biological function. You already met amino acids, peptide bonds and levels of protein structure; here the focus narrows to two broad protein types that OCR names directly: globular proteins and fibrous proteins. You will use haemoglobin, a named enzyme...
2.1.2(p) - Inorganic ions in biological processesInorganic ions are small charged particles, but they are involved in many of the biological processes you meet across the course. This lesson keeps the boundary tight: you need to recognise the required ion symbols, know whether each ion is positive or negative, and connect each one with a sensib...
2.1.2(q) - Chemical tests for biological moleculesThis lesson teaches how to carry out and interpret the four qualitative tests named in OCR Biology A for biological molecules. You will learn what each reagent shows, how to keep the method safe and valid, and how to turn a colour change into a careful biological conclusion without overclaiming.
2.1.2(r) - Colorimetry for concentration determinationIn this lesson you learn how a colorimeter can turn a colour change into a numerical estimate of concentration. The boundary is deliberately tight: the skill is using quantitative readings, known standards and a calibration curve to find the concentration of a chemical substance in solution. This...
2.1.2(s)(i)-(ii) - Paper and thin layer chromatographyIn this lesson you are learning how paper chromatography and thin layer chromatography separate biological compounds, how to run a valid practical investigation, and how to calculate and interpret Rf values. OCR cares about the method because a chromatogram is evidence: it can show whether a biol...
2.1.3 Nucleotides and nucleic acids
2.1.3(a)-(b) - Nucleotides and phosphodiester-linked polynucleotidesNucleic acids such as DNA and RNA are built from smaller monomers called nucleotides. In this lesson you will learn what a nucleotide contains, how DNA and RNA nucleotides differ, and how nucleotides join into polynucleotides through phosphodiester bonds. This is the molecular foundation for late...
2.1.3(c) - ADP and ATP as phosphorylated nucleotidesIn this lesson you are learning the structure of ADP and ATP as OCR expects it: both are phosphorylated nucleotides made from adenine, ribose and inorganic phosphate groups. The focus is deliberately narrow. Later lessons use ATP in respiration, photosynthesis, active transport and muscle contrac...
2.1.3(d)(i)-(ii) - DNA structure and DNA precipitationDNA stores genetic information because its structure is stable, specific and copyable. In this lesson you learn how two antiparallel DNA polynucleotides are held together by complementary base pairing, how this produces a double helix, and how a simple precipitation practical can release visible...
2.1.3(e) - Semi-conservative DNA replicationIn this lesson you learn how DNA can be copied before cell division while keeping the genetic information almost exactly the same. The key idea is semi-conservative replication: each new DNA molecule keeps one strand from the original molecule and gains one newly made complementary strand. You wi...
2.1.3(f) - The nature of the genetic codeIn this lesson you learn how the base sequence in a gene determines the sequence of amino acids in a polypeptide. The focus is the nature of the genetic code: it is triplet, non-overlapping, degenerate and universal. The lesson stays at the level of the code itself, with only a light bridge to mR...
2.1.3(g) - Transcription and translationIn this lesson you learn how the information in a gene is used to make a polypeptide. OCR expects the mechanism, not just the slogan "DNA makes protein": transcription makes an mRNA copy of the gene, then translation uses that mRNA at a ribosome to join amino acids in the correct sequence. The na...
2.1.4 Enzymes
2.1.4(a)-(b) - Enzymes as intracellular and extracellular catalystsThis lesson is about what enzymes do for living organisms, before the detailed mechanism of enzyme action is taught. You will learn why metabolism depends on enzyme-catalysed reactions, how enzymes affect both structure and function, and how to use catalase and amylase as precise examples of intr...
2.1.4(c) - Mechanism of enzyme actionEnzymes speed up metabolic reactions because their three-dimensional structure lets specific substrates bind and react more easily. In this lesson you will learn how the active site, lock and key model, induced-fit model, enzyme-substrate complex, enzyme-product complex and activation energy fit...
2.1.4(d)(i)-(ii) - Factors affecting enzyme activity and enzyme practicalsEnzyme activity means the rate of an enzyme-controlled reaction under a stated set of conditions. In this lesson you will learn how temperature, pH, enzyme concentration and substrate concentration change enzyme activity, how to calculate Q10, and how to design and interpret PAG4-style enzyme-rat...
2.1.4(e) - Coenzymes and cofactorsSome enzyme-controlled reactions need a non-protein helper before the enzyme can work at its normal rate. In this lesson you will learn the course distinction between cofactors and coenzymes, why chloride ions matter for amylase, and how vitamins can provide sources of coenzymes. The practical th...
2.1.4(f) - Enzyme inhibitors and end-product inhibitionEnzyme inhibitors reduce the rate of enzyme-controlled reactions, but they do this in different ways. In this lesson you will learn how to distinguish competitive and non-competitive inhibition, how reversible and non-reversible inhibition affect enzyme activity, and how end-product inhibition co...
2.1.5 Biological membranes
2.1.5(a)-(b) - Membrane roles and the fluid mosaic modelMembranes are not just the edges of cells. They are working surfaces that separate aqueous spaces, organise reactions and allow cells to receive signals. In this lesson you will learn the OCR roles of membranes and then use the fluid mosaic model to explain how the named membrane components make...
2.1.5(c)(i)-(ii) - Factors affecting membrane permeabilityMembranes are not fixed plastic bags around cells. Their phospholipids and proteins move, and their structure can be disturbed by conditions such as temperature and solvents. In this lesson you will learn how those conditions affect permeability, and how beetroot practicals use pigment leakage an...
2.1.5(d)(i)-(ii) - Movement of molecules across membranes and model cellsCells survive because their membranes are selective boundaries, not sealed walls. In this lesson you will learn how molecules move across membranes by diffusion, facilitated diffusion, active transport, endocytosis and exocytosis. You will then use model-cell investigations to connect those ideas...
2.1.6 Cell division, cell diversity and cellular organisation
Module 3: Exchange and transport
3.1.1 Exchange surfaces
3.1.2 Transport in animals
3.1.3 Transport in plants
Module 4: Biodiversity, evolution and disease
4.1.1 Communicable diseases, disease prevention and the immune system
4.2.1 Biodiversity
4.2.2 Classification and evolution
Module 5: Communication, homeostasis and energy
5.1.1 Communication and homeostasis
5.1.2 Excretion as an example of homeostatic control
5.1.3 Neuronal communication
5.1.4 Hormonal communication
5.1.5 Plant and animal responses
5.2.1 Photosynthesis
5.2.2 Respiration
Module 6: Genetics, evolution and ecosystems
6.1.1 Cellular control
6.1.2 Patterns of inheritance
6.1.3 Manipulating genomes
6.2.1 Cloning and biotechnology
6.3.1 Ecosystems
6.3.2 Populations and sustainability