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Edexcel International A Level · Biology

Energy, Environment, Microbiology and Immunity(Unit 4) revisionBuild it yourself.

Unit 4 covers 2 topics and 23 subtopics. Pick the ones you keep getting wrong and LOCKIN writes you an original exam-style paper, with a full mark scheme.

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What's in Unit 4

Every topic below can be selected on its own, or combined into one paper.

Energy Flow, Ecosystems and the Environment

  • Photosynthesis overview and ATP
  • Light-dependent reactions
  • Light-independent reactions
  • Chloroplast structure
  • Photosynthetic pigments and spectra
  • Productivity and energy transfer
  • Populations and communities
  • Succession
  • Climate change: evidence and causes
  • Effects of climate change
  • Evolution and speciation
  • Sustainability and reforestation

Usually 2–10 marks

Microbiology, Immunity and Forensics

  • Culturing microorganisms
  • Bacterial growth curves
  • Bacteria and viruses
  • Infection and non-specific responses
  • Antigens, antibodies and immune response
  • Types of immunity and vaccination
  • Antibiotics and resistance
  • Decomposition and nutrient cycling
  • PCR and gel electrophoresis
  • DNA profiling
  • Determining time of death

Usually 2–10 marks

Other Biology units

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