AQA GCSE Biology Paper 1 Summary

This guide covers key topics for AQA GCSE Biology Paper 1, including cells, organization, infection and response, and bioenergetics. Suitable for higher and foundation tiers, as well as double combined trilogy and triple biology.

Cells

• Microscopes:

  • Light microscopes can see cells and nuclei.
  • Electron microscopes reveal finer details (organelles).
  • Magnification Calculation: Image size / Object size.

• Cell Types:

  • Eukaryotic: Have a nucleus (e.g., animal and plant cells).
  • Prokaryotic: No nucleus.

• Cell Structures:

  • Cell Membrane: Semi-permeable, retains cell contents.
  • Cell Wall: Provides rigidity (in plants).
  • Cytoplasm: Site for chemical reactions.
  • Mitochondria: Site of respiration.
  • Ribosomes: Protein synthesis.
  • Chloroplasts: Photosynthesis (plants).
  • Vacuole: Stores sap (plants).

• Practical Work:

  • Bacteria culture in Petri dishes using aseptic techniques.

Cell Division

• Mitosis: For growth and repair.
  • Process: Genetic material duplicates > Nucleus divides > Two identical cells.
• Specialized Cells & Stem Cells:
  • Differentiation based on function.
  • Stem cells can become various cell types.
  • Applications: Treating diseases like diabetes and paralysis.
  • Ethical Issues: Cloning and use of stem cells.

Diffusion, Osmosis, and Active Transport

• Diffusion: Passive movement from high to low concentration.
• Osmosis: Specifically water diffusion across membranes.
• Active Transport: Movement against concentration gradient using energy.

Organization and Digestive System

• Tissues, Organs, and Systems:

  • Tissues form organs; organs form systems.

• Digestive System:

  • Breaks down food into nutrients.
  • Enzymes and bile aid digestion.
  • Enzymes: Amylase, protease, lipase.
  • Lock and Key Theory: Specificity of enzymes.

Respiratory and Circulatory Systems

• Breathing & Gas Exchange:

  • Oxygen diffuses into blood in the alveoli.

• Heart and Circulatory System:

  • Double circulation: Heart pumps blood into lungs and body.
  • Heart Structure: Chambers and flow of blood.
  • Blood Vessels: Arteries, veins, and capillaries.
  • Coronary Artery: Supplies heart muscle.

Diseases

• Communicable vs Non-Communicable:

  • Non-communicable: Lifestyle diseases, cancer.
  • Communicable: Caused by pathogens.

• Pathogens: Viruses, bacteria, fungi, protists.

• Body Defenses:

  • Skin, mucus, white blood cells.
  • Vaccination: Induces immunity.

Bioenergetics

• Photosynthesis:

  • Endothermic reaction producing glucose and oxygen.
  • Factors: Light, temperature, CO2.

• Respiration:

  • Aerobic vs anaerobic (produces lactic acid).
  • Metabolism: Sum of all biochemical reactions in an organism.

This guide encapsulates the essential topics and practicals for AQA GCSE Biology Paper 1, designed to provide an overview of the material covered in the examination.