GCSE Biology
Cells and organisation
revision.
Cell structure, microscopy, transport, enzymes and the jump from cells to systems.
Cells and organisation guides
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Students type: blood components GCSE Biology
Open guide Revision guidePlant hormonesStudents type: auxin phototropism GCSE Biology
Open guide Revision guideDigestive enzymesStudents type: amylase protease lipase GCSE locations
Open guide Revision guideHeart dissection required practicalStudents type: heart dissection GCSE Biology practical
Open guide Revision guideExchange surfacesStudents type: exchange surfaces adaptations GCSE Biology
Open guide Revision guideRoot hair cellsStudents type: root hair cell adaptations GCSE
Open guide Revision guideDiffusion in plantsStudents type: gas exchange in leaves GCSE
Open guide Revision guideBlood glucose controlStudents type: insulin glucagon blood glucose GCSE
Open guide Revision guideLevels of organisationStudents type: levels of organisation cells tissues organs GCSE
Open guide Revision guideThe eyeStudents type: eye accommodation GCSE Biology
Open guide Revision guideThe brainStudents type: brain regions GCSE Biology cortex cerebellum medulla
Open guide Revision guidePlant transportStudents type: xylem phloem comparison GCSE
Open guideCell biology
Eukaryotic and prokaryotic cells, organelles, specialised cells, microscopy and magnification — the flagship opening of GCSE Biology.
Osmosis and transport
Diffusion, osmosis and active transport: concentration gradients, partially permeable membranes and the potato practical.
Enzymes
Biological catalysts, the lock and key model, optimum conditions, denaturation and the amylase required practical.
Cell division and stem cells
The cell cycle, mitosis, meristems, embryonic and adult stem cells, and the ethics of therapeutic cloning.
Eukaryotic and prokaryotic cells
Compare eukaryotic and prokaryotic cells for GCSE Biology: nucleus versus a DNA loop, plasmids, organelles, and the diagram tests that decide Combined and Triple marks.
Animal and plant cells
Label animal and plant cells for GCSE Biology: nucleus, mitochondria, ribosomes, cellulose wall, chloroplasts, vacuole, and the structure–function links examiners actually mark.
Specialised cells
Link structure to function in GCSE Biology specialised cells: sperm, egg, nerve, muscle, root hair, palisade, xylem and phloem, with the adaptation sentences that score.
Microscopy and magnification
Calculate magnification for GCSE Biology, convert mm to µm to nm, and compare light and electron microscopes on resolution, living specimens and which organelles you can actually see.
Bacterial cells
Label a bacterial cell for GCSE Biology: chromosomal DNA loop, plasmids, flagella, cell wall, cytoplasm and membrane, and why bacteria lack a nucleus and mitochondria.
Diffusion
Define diffusion for GCSE Biology: net movement down a concentration gradient, no energy from respiration, and the factors that speed gas exchange in alveoli, leaves and villi.
Osmosis
Define osmosis for GCSE Biology: water from a dilute to a more concentrated solution through a partially permeable membrane, turgor, plasmolysis and the potato-chip graph.
Active transport
Explain active transport for GCSE Biology: movement against a concentration gradient using energy from respiration, root-hair mineral ions, and why mitochondria pack into those cells.
Osmosis required practical
Plan the GCSE Biology potato-chip osmosis practical: independent, dependent and control variables, percentage change in mass, blotting, and how the graph crosses zero at the isotonic point.
Enzyme active site
Explain the lock-and-key model for GCSE Biology: enzymes as protein catalysts, complementary active sites, specificity, and why a changed shape means the reaction stops.
Enzyme temperature and pH
Read enzyme graphs for GCSE Biology: rate rises with temperature to an optimum, then falls as the active site denatures, and pH peaks in a bell curve around pepsin, amylase or trypsin.
Amylase required practical
Run the GCSE Biology amylase–starch practical: iodine end-point, water baths, buffers, 1/time as rate, and how to investigate temperature or pH without mixing up the variables.
Mitosis
Describe mitosis for GCSE Biology: DNA replication, two genetically identical diploid body cells, and why growth, repair and asexual reproduction use mitosis — not meiosis.
Meiosis
Explain meiosis for GCSE Biology: two divisions, four genetically different haploid gametes, 46 to 23 chromosomes, and why fertilisation then restores the diploid number.
Stem cells
Compare embryonic, adult and meristem stem cells for GCSE Biology: unspecialised cells that can differentiate, bone-marrow treatments, therapeutic cloning, and the ethics examiners expect.
Cancer and tumours
Explain cancer for GCSE Biology: uncontrolled mitosis, benign versus malignant tumours, secondary tumours (metastasis), and lifestyle and genetic risk factors in Combined and Triple language.
Food tests required practical
Plan the GCSE Biology food-tests required practical: Benedict’s for reducing sugars, iodine for starch, biuret for protein, Sudan III for lipids, safety, controls and how to read a positive result.
Digestion
Explain the human digestive system for GCSE Biology: organs in order, mechanical and chemical digestion, enzymes, bile, peristalsis and absorption in the small intestine.
Circulation
Describe the circulatory system for GCSE Biology: heart chambers and vessels, double circulation, and the roles of red and white blood cells.
Transpiration
Explain transpiration for GCSE Biology: water loss from leaves, the transpiration stream, xylem transport and factors that increase or decrease the rate.
Plant transport
Compare xylem and phloem for GCSE Biology: transpiration stream, translocation of sucrose, and how root hair cells link water and mineral uptake to both tissues.
The brain
Describe the brain and CNS for GCSE Biology: main regions, their roles, and how the brain coordinates responses as part of the nervous system.
The eye
Explain eye structure and function for GCSE Biology: cornea, lens, retina, accommodation, pupil reflex and how the eye responds to bright light.
Levels of organisation
Explain how cells form tissues, organs and systems for GCSE Biology, with examples and links to stem cells and specialisation.
Blood glucose control
Explain how the pancreas, insulin and glucagon control blood glucose for GCSE Biology, with emphasis on liver, muscle and organisational links to homeostasis.
Diffusion in plants
Explain gas exchange in leaves for GCSE Biology: diffusion of carbon dioxide and oxygen, stomata, guard cells and links to photosynthesis and respiration.
Root hair cells
Specialised root hair cells for GCSE Biology: adaptations for water and mineral uptake, osmosis, active transport and links to xylem transport.
Exchange surfaces
General principles of exchange surfaces for GCSE Biology: adaptations for efficient diffusion and active transport beyond alveoli — villi, root hairs, leaves and fish gills.
Heart dissection required practical
Plan the GCSE Biology heart observation or dissection practical: identifying chambers, vessels, valves, thickness of ventricle walls and safe technique.
Digestive enzymes
Locate amylase, protease and lipase in the digestive system for GCSE Biology: where each is made, its substrate, products and optimum conditions.
Plant hormones
Define auxin, phototropism and gravitropism for GCSE Biology: unequal distribution of auxin, shoot and root responses, gibberellins in germination and stem elongation, and commercial uses in agriculture.
Blood components
GCSE Biology revision on blood: plasma, red blood cells, white blood cells and platelets — structure, function, and how each component is adapted for transport, defence or clotting.
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More GCSE Biology
in the same style.
Teacher-written GCSE Biology revision for Combined and Triple Science: cell structure, osmosis, enzymes, photosynthesis, respiration, infection, homeostasis, inheritance and ecology.
All Biology revision