BRAINCAKE

OCR A-level Biology

OCR Biology A (H420)12 topics277 lessons

OCR A-level Biology revision for OCR Biology A (H420): 12 topics and 277 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. Homeostasis

33 lessonsSpec 5.1.1, 5.1.2

  1. Homeostasis
  2. Feedback Systems
  3. Examples of Positive Feedback
  4. Endotherms and Ectotherms
  5. Behavioural Responses in Ectotherms
  6. Physiological Responses in Ectotherms
  7. Thermoreceptors
  8. The Hypothalamus
  9. Cooling
  10. Warming Up
  11. Excretion
  12. The Liver
  13. Structure of the Liver
  14. Carbohydrate Metabolism in the Liver
  15. Transamination and Deamination
  16. Detoxification
  17. Production of Bile Salts, Bile Pigments and Cholesterol
  18. The Kidneys
  19. Structure of the Kidney
  20. Nephrons
  21. Bowman's Capsule
  22. Glomerulus
  23. Proximal Convoluted Tubule
  24. Loop of Henlé
  25. Countercurrent Multiplier
  26. Ultrafiltration, Selective Reabsorption and Osmoregulation.
  27. Distal Tubule and Collecting Duct
  28. ADH
  29. Kidney failure
  30. Haemodialysis
  31. Peritoneal Dialysis
  32. Pregnancy Testing
  33. Anabolic Steroids

2. Neuronal Communication

38 lessonsSpec 5.1.1, 5.1.3

  1. Co-ordination
  2. Homeostasis
  3. Cell Signalling
  4. The Nervous System
  5. Neurones
  6. Sensory Neurones
  7. Motor Neurones
  8. Myelinated Neurones
  9. Sensory Receptors
  10. Pacinian Corpuscles
  11. Generator Potential
  12. Resting Potential
  13. Depolarisation
  14. Repolarisation
  15. Hyperpolarisation
  16. The Action Potential
  17. Nerve Impulse
  18. Saltatory Conduction
  19. Synapses
  20. Neurotransmitters
  21. Transmission of Impulse across Synapse
  22. The Role of Synapses
  23. Summation
  24. Structural Organisation of the Nervous System
  25. Functional Organisation of the Nervous System
  26. The Autonomic Nervous System
  27. Comparison of Neurones
  28. The Brain
  29. Structure of the Brain
  30. Cerebrum
  31. Association Areas
  32. Cerebellum
  33. Medulla Oblongata
  34. Hypothalamus
  35. Pituitary Gland
  36. Reflex Actions
  37. Knee-jerk Reflex
  38. Blinking Reflex

3. Hormonal Communication

19 lessonsSpec 5.1.4

  1. Endocrine Glands
  2. Hormones
  3. The Adrenal Glands
  4. Adrenal Cortex
  5. Adrenal Medulla
  6. Pancreas
  7. Blood glucose concentration
  8. Insulin
  9. Glucagon
  10. Mechanism of Insulin Secretion
  11. Diabetes Mellitus
  12. The Fight or Flight Response
  13. Coordinating Nervous and Hormonal Responses
  14. Adrenaline and the Second Messenger Model
  15. The Cardiovascular Centre in the Medulla
  16. Control of Heart Rate
  17. Baroreceptors
  18. Chemoreceptors
  19. Hormonal Control of Heart Rate

4. Muscles

15 lessonsSpec 5.1.5

  1. Types of Muscle
  2. Difference in Structure of Different Types of Muscle
  3. Cardiac Muscle
  4. Smooth Muscle
  5. Muscle Fibres
  6. Myofibrils
  7. Actin
  8. Myosin
  9. A Sarcomere
  10. Neuromuscular Junction
  11. Sliding Filament Model
  12. Release of Calcium Ions into the Sarcoplasm
  13. The Power Stroke
  14. The Role of Ca2+ and ATP in Muscle Contraction
  15. Energy Supply during Muscle Contraction

5. Plant Responses

19 lessonsSpec 5.1.5

  1. Plant Growth Responses
  2. Plant Hormones
  3. Seed Germination
  4. Auxins and Cell Elongation
  5. Gibberellins: Synergy and Antagonism.
  6. Leaf Loss
  7. Flowering and Day-Length
  8. Preventing Freezing
  9. Stomatal Control
  10. Chemical Defences
  11. Pheromones
  12. Response to Touch
  13. Tropisms
  14. Growing in the Dark
  15. Geotropism
  16. Fruit Ripening
  17. Rooting Powder
  18. Hormonal Weedkillers
  19. Other Uses of Plant Hormones

6. Energy for Biological Processes

17 lessonsSpec 5.2.1

  1. ATP
  2. Chloroplasts
  3. Photosynthetic pigments
  4. Photosystems
  5. Cyclic Photophosphorylation
  6. Non-cyclic Photophosphorylation
  7. Chemiosmosis
  8. Calvin Cycle
  9. Limiting Factors of Photosynthesis
  10. Light Intensity as a Limiting Factor
  11. Carbon Dioxide Concentration as a Limiting Factor
  12. Temperature as a Limiting Factor
  13. Interpreting Limiting Factor Graphs
  14. Effect of Limiting Factors on the Calvin Cycle
  15. Uses of Triose Phosphate
  16. Investigating the Rate of Photosynthesis
  17. Agricultural Glasshouses and Limiting Factors

7. Respiration

19 lessonsSpec 5.2.2

  1. Energy from Glucose.
  2. Glycolysis
  3. Phosphorylation
  4. Lysis
  5. Substrate Level Phosphorylation
  6. The Link Reaction
  7. The Krebs Cycle.
  8. Oxidative Phosphorylation
  9. ATP Synthase
  10. Creatine Phosphate
  11. Anaerobic Respiration - Plants and Microorganisms.
  12. Anaerobic Respiration - Mammals
  13. Respiratory Substrates
  14. Energy Values of Carbohydrates, Lipids and Proteins
  15. Respiration of Lipids
  16. Respiration of Proteins
  17. Respiratory Quotient
  18. Calculating RQ
  19. Measuring RQ with a Respirometer

8. Genetics and Variation

41 lessonsSpec 6.1.1, 6.1.2

  1. The Genetic Code
  2. Mutations
  3. Effects of Mutations
  4. Change in Protein Function
  5. Sickle-cell Anaemia
  6. Causes of mutations
  7. Chromosome Mutations
  8. Gene Regulation
  9. Controlling Transcription
  10. Lac Operon
  11. cyclic AMP
  12. Post-transcriptional control
  13. Translational Control
  14. Post-translational Control
  15. Homeobox Genes
  16. Body Plans
  17. Apoptosis
  18. Regulatory Genes
  19. Variation
  20. Body Mass
  21. Genetic Variation
  22. Continuous and Discontinuous Variation
  23. Genetic Cross
  24. Sex Linkage
  25. Dihybrid Crosses
  26. Linkage
  27. Χ-squared Test
  28. Epistasis
  29. The Hardy-Weinberg Principle
  30. Changes in Allele Frequencies
  31. Population Bottlenecks and The Founder Effect
  32. Types of Selection
  33. Species
  34. Allopatric Speciation
  35. Sympatric Speciation
  36. Artificial Selection
  37. Codominance
  38. Codominance Genetic Crosses
  39. Multiple Alleles
  40. Multiple Allele Crosses - ABO Blood Groups
  41. Autosomal Linkage and Recombinant Offspring

9. Genetic Engineering and Biotechnology

17 lessonsSpec 6.1.3

  1. Non-coding DNA
  2. Gel Electrophoresis
  3. DNA Profiling
  4. The Polymerase Chain Reaction
  5. DNA Sequencing
  6. Automated Sequencing
  7. Pathogens, DNA Barcoding
  8. Genomics and Proteomics
  9. Recombinant DNA
  10. Genetic Engineering
  11. Genetically Engineering Different Organisms
  12. Genetically Engineering Plants
  13. Ethical Concerns - microorganisms
  14. GM plants
  15. Patenting
  16. GM animals
  17. Gene Therapy

10. Cloning and Biotechnology

21 lessonsSpec 6.2.1

  1. Natural Clones in Plants
  2. Vegetative Propagation
  3. Artificial Clones - Cuttings
  4. Tissue Culture and Micropropagation
  5. Pros and Cons of Plant Cloning
  6. Natural Clones in Animals
  7. Artificial Twinning
  8. Somatic Cell Nuclear Transfer
  9. Pros and Cons of Animal Cloning
  10. Microorganisms in Biotechnology
  11. Microorganisms in Food Production
  12. Microorganisms in Medicine and Bioremediation
  13. Culturing Microorganisms
  14. Aseptic Technique
  15. Serial Dilution
  16. Standard Growth Curve
  17. Batch Fermentation
  18. Continuous Fermentation
  19. Controlling Conditions in Fermenters
  20. Immobilised Enzymes
  21. Uses of Immobilised Enzymes

11. Ecosystems

21 lessonsSpec 6.3.1

  1. Ecosystems
  2. Biotic Factors
  3. Abiotic Factors
  4. Producers and Consumers
  5. Trophic Levels
  6. Biomass Transfer
  7. Ecological Efficiency
  8. Calculating Efficiency of Biomass Transfer
  9. Human Activities and Biomass Transfer
  10. Decomposers
  11. The Nitrogen Cycle
  12. Nitrogen-Fixing Bacteria
  13. Nitrification and Denitrification
  14. The Carbon Cycle
  15. Succession
  16. Primary Succession
  17. Secondary Succession
  18. Deflected Succession
  19. Sampling Distribution and Abundance
  20. Quadrats and Transects
  21. Measuring Abiotic Factors in the Field

12. Populations and Sustainability

17 lessonsSpec 6.3.2

  1. Population Size
  2. Carrying Capacity
  3. Limiting Factors of Population Size
  4. Density-Dependent and Density-Independent Factors
  5. Predator-Prey Relationships
  6. Interspecific Competition
  7. Intraspecific Competition
  8. Conservation
  9. Preservation
  10. Sustainability
  11. Sustainable Timber Production - Coppicing
  12. Sustainable Fishing
  13. Managing Ecosystems - Masai Mara
  14. Managing Ecosystems - Terai Region
  15. Managing Ecosystems - Peat Bogs
  16. Managing Environmentally Sensitive Ecosystems - Galapagos
  17. Managing Environmentally Sensitive Ecosystems - Antarctica