AQA GCSE Biology Paper 1 Summary

Overview

• Covers all necessary topics for AQA GCSE Biology Paper 1.
• Suitable for higher and foundation tier, double combined trilogy, and triple or separate biology.

Core Topics

• Cells
• Organization
• Infection and Response
• Bioenergetics

Cells

• All life is made up of cells; visible with a light microscope.
• Electron microscopes provide detailed views of organelles.
• Magnification Formula: Magnification = Image size / Object size.
• Types of Cells:
  • Eukaryotic Cells: Contain a nucleus (e.g., plant and animal cells).
  • Prokaryotic Cells: Do not have a nucleus.
• Cell Structures:
  • Cell membrane: Semi-permeable.
  • Cell wall: Provides structure (in plants and bacteria).
  • Cytoplasm: Site of chemical reactions.
  • Mitochondria: Respiration occurs here.
  • Ribosomes: Protein synthesis.
  • Chloroplasts (plants): Photosynthesis.
  • Vacuole (plants): Stores sap.
• Cell Division (Mitosis): Produces two identical cells.
• Stem Cells: Can specialize into different cell types.

Microscopy

• Practical on Bacteria Culture: Involves aseptic techniques and antibiotic testing.

Genetic Material

• DNA stored in chromosomes within the nucleus.
• Human cells have 23 pairs of chromosomes (diploid).
• Gametes have 23 individual chromosomes (haploid).

Diffusion and Osmosis

• Diffusion: Movement from high to low concentration; passive.
• Osmosis: Diffusion of water across a semi-permeable membrane.
• Factors Affecting Rate: Concentration gradient, temperature, surface area.
• Osmosis Practical: Using potato cylinders in varying sugar solutions.

Active Transport

• Movement against a concentration gradient using energy.

Organization

• Tissues: Groups of similar cells.
• Organs: Made from tissues, e.g., heart.
• Organ Systems: Digestive system breaks down food using enzymes.
• Enzymes: Biological catalysts, specific to substrates; affected by temperature and pH.
• Enzyme Activity Practical: Involves starch breakdown by amylase.

Respiratory System

• Breathing and Gas Exchange: Oxygen enters lungs, CO2 exhaled.
• Heart Function: Circulates oxygenated and deoxygenated blood.
• Blood Vessels: Arteries (away from heart), veins (toward heart).
• Heart Disease: CHD, stents, and statins.
• Blood Composition: Red and white blood cells, platelets.

Non-Communicable Diseases

• Examples: Diabetes, heart disease, liver disease.
• Cancer: Benign vs. malignant.

Plant Biology

• Photosynthesis: Occurs in chloroplasts; factors affecting rate include light and CO2.
• Plant Structures: Leaves, roots, xylem, and phloem.

Infection and Response

• Pathogens: Viruses, bacteria, fungi, and protists.
• Immune Response: Involves white blood cells, antibodies, vaccines.
• Vaccines: Expose immune system to inert pathogens.
• Antibiotics: Kill bacteria, not viruses.
• Drug Trials: Blind and double-blind trials.

Bioenergetics

• Photosynthesis: Endothermic reaction providing food for plants.
• Respiration: Aerobic (with oxygen) and anaerobic (without oxygen).
• Metabolism: Sum of all reactions in a cell.

Conclusion

• The lecture provides an extensive overview of the essential concepts and practicals needed for the AQA GCSE Biology Paper 1.
• Encourage review of practicals and application of concepts in real-world biology scenarios.