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OCR AS-level Biology

OCR Biology A (H020)12 topics352 lessons

Free OCR AS-level Biology revision for OCR Biology A (H020): 12 topics and 352 short lessons, each with R.E.C.I.P.E. recall steps and a quiz. The topics follow the OCR specification.

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1. Components of Living Systems

21 lessons

  1. Development of Cell Theory
  2. The Light Microscope
  3. Preparing Samples
  4. Staining
  5. Gram Stain
  6. Acid-Fast Technique
  7. Magnification
  8. Resolution
  9. The Eyepiece Graticule
  10. Electron Microscopy
  11. Transmission Electron Microscope
  12. Scanning Electron Microscope
  13. Sample Preparation for Electron Microscopes
  14. Differences Between Light and Electron Microscopes
  15. Scientific Drawings
  16. Artefacts
  17. Laser Scanning Confocal Microscopy
  18. Fluorescent Tags
  19. Atomic Force Microscopy
  20. Super Resolved Fluorescence Microscopy
  21. Relative Sizes

2. Cell Structure

26 lessons

  1. Eukaryotic Cell Structure
  2. Compartmentalisation
  3. Nucleus
  4. Nucleolus
  5. Mitochondria
  6. Vesicles
  7. Lysosomes
  8. The Cytoskeleton
  9. Cell Movement
  10. Centrioles
  11. Cilia and Flagella
  12. Smooth Endoplasmic Reticulum
  13. Ribosomes
  14. Rough Endoplasmic Reticulum
  15. Golgi Apparatus
  16. Plant Cells
  17. Cellulose Cell Wall
  18. Vacuole
  19. Chloroplasts
  20. Prokaryotic Cells
  21. DNA
  22. Ribosomes
  23. Cell Wall
  24. Flagella
  25. The Theory of Endosymbiosis
  26. Comparison with Eukaryotic Cells

3. Biological Molecules

63 lessons

  1. Elements
  2. Bonding
  3. Ions
  4. Biological Molecules
  5. Polymers
  6. Water
  7. Hydrogen Bonding and Boiling Point of Water
  8. Density of Water
  9. Cohesion, Adhesion and Surface Tension
  10. Specific Heat Capacity of Water
  11. Water as a Solvent
  12. Carbohydrates
  13. Glucose
  14. Other Monosaccharides
  15. Condensation Reactions
  16. Hydrolysis
  17. Disaccharides
  18. Test for Reducing Sugars
  19. Test for Non-Reducing Sugars
  20. Starch
  21. Test for Starch
  22. Colorimetry
  23. Glycogen
  24. Cellulose
  25. Biosensors
  26. Lipids
  27. Triglycerides
  28. Saturated and Unsaturated Fatty Acids
  29. Phospholipids
  30. Sterols
  31. Roles of Lipids
  32. Test for Lipids
  33. Lipids and Health
  34. Amino-acids
  35. Thin Layer Chromatography
  36. Polypeptides
  37. Protein Structure
  38. Hydrolysis of Peptides
  39. Globular Proteins
  40. Insulin
  41. Conjugated Proteins
  42. Haemoglobin
  43. Catalase
  44. Fibrous Proteins
  45. Keratin
  46. Elastin
  47. Collagen
  48. Test for Proteins
  49. Nucleotides
  50. DNA
  51. RNA
  52. DNA Extraction
  53. Role of RNA
  54. DNA Replication
  55. Continuous and Dis-continuous Replication
  56. Replication Errors
  57. The Genetic Code
  58. Protein Synthesis
  59. The role of tRNA, mRNA and rRNA
  60. Transcription
  61. Splicing
  62. Translation
  63. ATP

4. Enzymes

20 lessons

  1. The Role of Enzymes
  2. The Mechanism of Enzyme Action
  3. Lock and Key Hypothesis
  4. Induced-Fit Hypothesis
  5. Intracellular Enzymes
  6. Extracellular Enzymes
  7. Amylase
  8. Proteases
  9. Effect of Temperature on Enzyme Activity
  10. Temperature Extremes
  11. Effect of pH on Enzyme Activity
  12. Enzyme Concentration
  13. Substrate Concentration
  14. Competitive Inhibition
  15. Non-competitive Inhibition
  16. End-Product Inhibition
  17. Cofactors
  18. Coenzymes
  19. Prosthetic Groups
  20. Precursor Activation

5. Plasma Membrane

18 lessons

  1. Membrane Structure
  2. Fluid Mosaic Model
  3. Membrane Proteins
  4. Glycoproteins
  5. Glycolipids
  6. Extrinsic Proteins
  7. Cholesterol
  8. Sites of Chemical Reactions
  9. Effect of Temperature
  10. Solvents
  11. Diffusion
  12. Diffusion Across Membranes
  13. Facilitated Diffusion
  14. Active Transport
  15. Bulk Transport
  16. Osmosis
  17. Osmosis in Animal Cells
  18. Osmosis in Plant Cells

6. Cell Division

31 lessons

  1. The Cell Cycle
  2. Interphase
  3. Mitosis
  4. Control of the Cell Cycle
  5. Cancer
  6. Chromosomes
  7. Prophase
  8. Metaphase
  9. Telophase
  10. Cytokinesis
  11. Meiosis
  12. Homologous Chromosomes
  13. The Stages of Meiosis
  14. Prophase 1
  15. Metaphase 1
  16. Anaphase 1
  17. Telophase 1
  18. Meiosis 2
  19. Specialised Cells and Tissues
  20. Epithelial Cells
  21. Specialised Plant Cells
  22. Organs and Organ Systems
  23. Stem Cells
  24. Stem Cell Potency
  25. Differentiation
  26. Replacement of Red and White Blood Cells
  27. Sources of Animal Stem Cells
  28. Sources of Plant Stem Cells
  29. Uses of Stem Cells
  30. Ethics
  31. Anaphase

7. Exchange Surfaces and Breathing

24 lessons

  1. The Need for Specialised Exchange Surfaces
  2. Surface Area to Volume Ratio
  3. Specialised Exchange Surfaces
  4. The Human Gas Exchange System
  5. The Lungs
  6. Mechanism of Breathing
  7. Inspiration
  8. Expiration
  9. Alveoli
  10. Role of Alveoli in Gas Exchange
  11. Asthma
  12. The First Breath
  13. Measuring Lung Capacity
  14. Lung Volume
  15. Breathing Rate and Ventilation Rate
  16. Gas Exchange in Unicellular Organisms
  17. Gas Exchange in Insects
  18. Diffusion Gradient
  19. Mass Transport
  20. Increasing the Rate of Diffusion
  21. Limitations of the Tracheal System
  22. Gas Exchange in Fish
  23. Structure of the Gills
  24. Counter Current Exchange

8. Transport in Animals

22 lessons

  1. Specialised Transport Systems
  2. Features of a Transport System
  3. Types of Circulatory System
  4. Open Circulatory Systems
  5. Closed Circulatory Systems
  6. Single Closed Circulatory Systems
  7. Double Closed Circulatory Systems
  8. Blood Vessels
  9. Arteries
  10. Arterioles
  11. Veins and Venules
  12. Capillaries
  13. Tissue Fluid
  14. Return of Tissue Fluid to Blood
  15. Chloride Shift
  16. Human Heart
  17. Structure and Function of the Heart
  18. Cardiac Cycle
  19. Heart Sounds
  20. Basic Rhythm of the Heart
  21. Electrocardiograms
  22. Aortic Aneurysms

9. Mass Transport in Plants

18 lessons

  1. Specialised Plant Cells
  2. Transpiration
  3. Movement of Water into the Root Hair Cells
  4. Movement of Water across the Roots
  5. Movement of Water Up the Stem
  6. Movement of Water Across the Leaf
  7. Movement of Water Through the Stomata
  8. Translocation
  9. Phloem Loading
  10. Mass Flow through Sieve Tube Elements
  11. Mass Flow Model
  12. Phloem Unloading
  13. Ringing Experiments
  14. Tracer Experiments
  15. Evidence for Translocation in Phloem
  16. Xerophytes
  17. Limiting Water Loss in Plants
  18. Hydrophytes

10. Classification and Evolution

36 lessons

  1. Classification
  2. Classifying Organisms
  3. Naming Organisms
  4. The Five Kingdoms
  5. Prokaryotae
  6. Protictista
  7. Fungi
  8. Plantae
  9. Animalia
  10. Classification
  11. The Three Domain System
  12. Archaebacteria and Eubacteria
  13. Phylogeny
  14. Advantages of Phylogenetic Classification
  15. Theory of Evolution
  16. Evidence for Evolution
  17. Palaeontology
  18. Comparative Anatomy
  19. Comparative Biochemistry
  20. Types of Variation
  21. Genetic Causes of Variation - Mutation
  22. Genetic Causes of Variation - Meiosis and Chance
  23. Environmental Causes of Variation
  24. Discontinuous Variation
  25. Continuous Variation
  26. Normal Distribution
  27. Standard Deviation
  28. Student T-test
  29. Spearman's Rank Correlation Coefficient
  30. Adaptations
  31. Anatomical Adaptations
  32. Courtship Behaviour
  33. Physiological Adaptations
  34. Convergent Evolution
  35. Natural Selection
  36. Modern Examples of Natural Selection

11. Biodiversity

33 lessons

  1. Importance of Biodiversity
  2. Measuring Biodiversity
  3. Habitat Biodiversity
  4. Species Biodiversity
  5. Genetic Biodiversity
  6. Sampling
  7. Random Sampling
  8. Non-Random Sampling
  9. Reliability
  10. Sampling Animals
  11. Sampling Plants
  12. Species Richness
  13. Species Evenness
  14. Frame Quadrats
  15. Estimating Population Size
  16. Measuring Abiotic Factors
  17. Simpson's Index of Diversity
  18. The Importance of Genetic Diversity
  19. Factors Affecting Genetic Biodiversity
  20. Measuring Genetic Biodiversity
  21. Human Influence of Biodiversity
  22. Deforestation
  23. Agriculture
  24. Climate Change
  25. Reasons for Maintaining Biodiversity
  26. Aesthetic Reasons
  27. Economic Reasons
  28. Ecological Reasons
  29. Human Activity and Biodiversity
  30. Maintaining Biodiversity
  31. In Situ Conservation
  32. Ex Situ Conservation
  33. Conservation Agreements

12. Communicable Diseases

40 lessons

  1. Types of Pathogens
  2. Bacteria
  3. Viruses
  4. Protoctists
  5. Fungi
  6. Modes of Action
  7. Plant Diseases
  8. Tuberculosis
  9. Bacterial Meningitis
  10. HIV/AIDS
  11. Influenza
  12. Zoonotic Influenza
  13. Malaria
  14. Fungal Diseases
  15. Transmission of Pathogens
  16. Factors Affecting Transmission in Animals
  17. Transmission of Pathogens Between Plants
  18. Plant Defences against Pathogens
  19. Mammals - non-Specific Defences
  20. Blood Clotting
  21. Inflammatory Response
  22. Fevers
  23. Phagocytosis
  24. Counting Blood Cells
  25. Cytokines
  26. Opsonins
  27. Antibodies
  28. How Antibodies Work
  29. Lymphocytes
  30. Cell-Mediated Immunity
  31. Humoral Immunity
  32. Auto-Immune Diseases
  33. Natural Immunity
  34. Artificial Passive Immunity
  35. Artificial Active Immunity
  36. Vaccines
  37. Sources of Medicines
  38. Drug Design
  39. Antibiotic Resistance
  40. MRSA and C. difficile