Edexcel International GCSE Biology (4BI1) revision notes
IGCSE Biology video lessons · Revision notes · IGCSE Biology past papers
Clear revision notes for every topic, each beside its video lesson.
1 Life processes
- The characteristics of living organisms notes
- Animal and plant cells under the microscope notes
- The light microscope and magnification notes
- Temperature, pH and denaturing notes
- Practical: measuring enzyme activity notes
- Anaerobic respiration and how it differs from aerobic notes
- Practical: enzymes and food notes
- Aerobic respiration and ATP notes
- Practical: showing that respiring seeds give out carbon dioxide and heat notes
- Diffusion notes
- Osmosis notes
- Active transport notes
- What changes the rate of movement notes
- Stem cells and differentiation notes
- Cells, tissues, organs and systems notes
- Enzymes and the active site notes
2 The variety of living organisms
- Plants, animals, fungi, protoctists and bacteria notes
- Features of plants and animals notes
- Fungi, protoctists and bacteria notes
- Viruses and the main pathogen groups notes
3 Breathing and gas exchange
- The parts of the breathing system notes
- Ventilation- ribs, intercostals and diaphragm notes
- Alveoli and how they are adapted notes
- Comparing inspired and expired air notes
- The effect of exercise on breathing notes
- The effects of smoking on the lungs and the circulation notes
4 Food and digestion
- Carbohydrates, proteins and lipids notes
- Testing for starch, sugars, protein and fat notes
- The seven parts of a balanced diet notes
- What changes how much energy you need notes
- The parts of the digestive system notes
- Teeth, chewing and peristalsis notes
- Amylase, protease and lipase notes
- Bile, the liver and emulsifying fat notes
- The villus and absorption notes
- Practical: measuring the energy in a food sample notes
5 Blood and circulation
- Why small organisms manage without a transport system and large ones cannot notes
- Double circulation notes
- The structure of the heart notes
- How the heart beats notes
- Coronary arteries and heart disease notes
- How heart rate changes during exercise and under adrenaline notes
- Adrenaline and the body's response notes
- Arteries, veins and capillaries notes
- Plasma, red cells, white cells and platelets notes
- Phagocytes, antibodies and clotting notes
- Vaccination, memory cells and the secondary response notes
6 Coordination
- Central and peripheral nervous system notes
- Comparing nervous and hormonal control notes
- The three types of neurone, and the synapse notes
- The structure of the eye notes
- Focusing on near and distant objects notes
- Bright light and dim light notes
- Reflex actions notes
7 Chemical coordination
- The endocrine system notes
- Insulin, glucagon and the pancreas notes
- Testosterone, oestrogen and puberty notes
- Controlling the water content of the blood notes
8 Homeostasis and excretion
- Homeostasis and negative feedback notes
- Lungs, kidneys and skin as excretory organs notes
- Stomata and guard cells notes
- Kidneys, ureters and bladder notes
- Ultrafiltration and selective reabsorption notes
- Sweating, shivering and blood vessels notes
9 Reproduction in humans
- Sperm, egg and fertilisation notes
- Runners, tubers and cuttings notes
- The human reproductive systems notes
- The placenta and the developing fetus notes
- Hormones and the menstrual cycle notes
10 Plants and food
- Practical: light, carbon dioxide and chlorophyll notes
- Practical: the starch test notes
- The photosynthesis reaction notes
- How a leaf is adapted notes
- Light, carbon dioxide and temperature notes
- Practical: the effect of light on net gas exchange in a leaf notes
- Nitrate, phosphate, potassium and magnesium notes
11 Transport in plants
- Root hair cells and water uptake notes
- The transpiration stream notes
- Where the tissues sit in the plant notes
- The two transport tissues notes
- Moving sugars from source to sink notes
- Practical: what changes the rate notes
12 Chemical coordination in plants
13 Reproduction in plants
- The parts of a flower notes
- Insect and wind pollination notes
- The pollen tube and fertilisation notes
- Seed structure and germination notes
14 Ecosystems
- Habitat, population, community, ecosystem notes
- Practical: quadrats and transects notes
- What biodiversity means and how it is measured notes
- Food chains and food webs notes
- Decomposers and decay notes
- Pyramids of number, biomass and energy notes
- Why energy is lost between levels notes
- The carbon cycle notes
- The nitrogen cycle notes
15 Human influences on the environment
- Glasshouses and polythene tunnels, and why they raise yield notes
- How fertilisers increase crop yield notes
- Pesticides and biological control notes
- Feeding people without emptying the sea notes
- Greenhouse gases and global warming notes
- How acid rain forms and what it does notes
- Sewage, carbon monoxide and sulfur dioxide notes
- The effects of cutting down forests notes
- Fertiliser, algae and dead water notes
- Sustainable resources and conservation notes
16 Chromosomes, genes and DNA
- How the nucleus, chromosome, gene and DNA fit together notes
- Genes, alleles and the genome notes
- The double helix and base pairing notes
- Transcription and translation notes
- Mutations and what causes them notes
- Allele, genotype, phenotype, dominant, recessive notes
17 Cell division
- Mitosis and growth notes
- Meiosis and gametes notes
- Telling the two apart in the exam notes
- Continuous and discontinuous variation notes
18 Genes and inheritance
- Punnett squares notes
- Ratios, and what they do not promise notes
- Reading a pedigree notes
- When neither allele wins notes
- X and Y chromosomes notes
- Why most characteristics are controlled by many genes notes
19 Natural selection and evolution
20 Selective breeding
- Breeding animals and crops for a purpose notes
- Comparing artificial and natural selection notes
- Micropropagation and cloning animals notes
- Transgenic organisms and using cloned animals to make human proteins notes
21 Using microorganisms
- Yeast, anaerobic respiration and bread notes
- Beer, wine and yoghurt notes
- Growing microorganisms at scale notes
- Practical: aseptic technique notes