📚

Overview of AQA GCSE Biology Paper 1

May 10, 2025

AQA GCSE Biology Paper 1 Overview

Topics Covered:

  • Cells
  • Organization
  • Infection and Response
  • Bioenergetics

Cells

  • Types of Cells:

    • Eukaryotic Cells: Have a nucleus; examples include plant and animal cells.
    • Prokaryotic Cells: Do not have a nucleus.

  • Microscopes:

    • Light microscopes can show cells and nuclei.
    • Electron microscopes provide detailed images of organelles.

  • Cell Structures:

    • Cell Membrane: Semi-permeable, allows certain substances through.
    • Cell Wall: Found in plant cells and most bacteria, provides rigidity.
    • Cytoplasm: Site of chemical reactions.
    • Mitochondria: Site of respiration.
    • Ribosomes: Protein synthesis.
    • Chloroplasts: Photosynthesis in plant cells.
    • Vacuole: Stores sap in plant cells.

  • Cell Processes:

    • Binary fission in bacteria.
    • Culturing bacteria using aseptic techniques.
    • DNA in eukaryotic cells is stored in chromosomes; humans have 23 pairs.
    • Mitosis: Cell division process for growth and repair.
    • Stem Cells: Undifferentiated cells capable of becoming specialized.
    • Diffusion and Osmosis: Movement of molecules across concentration gradients.
    • Active Transport: Movement of molecules against concentration gradients with energy.

Organization

  • Cell Specialization:

    • Nerve, muscle, root hair, xylem, and phloem cells.

  • Levels of Organization:

    • Tissues: Groups of similar cells (e.g., heart tissue).
    • Organs: Tissues working together (e.g., heart).
    • Organ Systems: Organs working together (e.g., circulatory system).

  • Digestive System:

    • Breaks down food into nutrients.
    • Enzymes like amylase break down large molecules.
    • Enzyme specificity and activity affected by temperature and pH.

Infection and Response

  • Pathogens:

    • Types: Viruses, bacteria, fungi, protists.
    • Viruses: Reproduce by injecting genetic material into cells.
    • Examples: Measles, HIV, Salmonella, Gonorrhea.

  • Body's Defense Mechanisms:

    • Skin, mucus, enzymes, immune system.
    • White blood cells, lymphocytes, phagocytes.
    • Vaccines: Introduce an inert pathogen to build immunity.
    • Antibiotics: Target bacteria, not viruses.

Bioenergetics

  • Photosynthesis:

    • Occurs in chloroplasts, uses light energy.
    • Produces glucose for respiration or storage.
    • Affected by temperature, light intensity, and CO2 levels.

  • Respiration:

    • Aerobic Respiration: With oxygen, produces energy.
    • Anaerobic Respiration: Without oxygen, produces lactic acid.
    • Fermentation in yeast produces ethanol and CO2.

  • Metabolism:

    • Sum of all chemical reactions in a cell or organism.
    • Includes respiration, protein synthesis, and conversion of molecules.

Additional Notes for Triple Science

  • Bacteria:

    • Multiply by binary fission; cultures can be grown using aseptic techniques.

  • Photosynthesis and Plant Transport:

    • Role of xylem and phloem in water and nutrient transport.

  • Monoclonal Antibodies:

    • Used for treatment and diagnosis; produced by combining lymphocytes with tumor cells.

This summary captures the essential points needed for students taking the AQA GCSE Biology Paper 1, covering both higher and foundation tiers, with additional details for triple science students.

Full transcript