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Overview of EDXL GCSE Biology Paper One

May 12, 2025

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EDXL GCSE Biology Paper One Overview

Key Topics

  • Key Concepts: Cells and control, Genetics, Natural Selection and Genetic Modification, Health, Disease, and Medicines.
  • Target Audience: Higher-end foundation tier, double combined or triple separate.

Cells and Microscopy

  • Cells: Basic unit of life. Visible with a light microscope; electron microscopes show sub-cellular structures.
  • Types of Cells:
    • Eukaryotic: Have a nucleus (e.g., plant and animal cells).
    • Prokaryotic: No nucleus.
  • Cell Structures:
    • Cell Membrane: Semi-permeable.
    • Cell Wall: Found in plants/bacteria, made of cellulose.
    • Cytoplasm: Site of chemical reactions.
    • Organelles: Mitochondria (respiration), Ribosomes (protein synthesis), Chloroplasts (photosynthesis in plants).

Enzymes

  • Function: Biological catalysts, specific to substrates (lock and key model).
  • Important Enzymes:
    • Amylase: Breaks down starch into glucose.
    • Proteases: Break proteins into amino acids.
    • Lipases: Break lipids into glycerol and fatty acids.
  • Factors Affecting Enzyme Activity: Temperature, pH (denaturation at extremes).

Diffusion, Osmosis, and Active Transport

  • Diffusion: Passive movement from high to low concentration.
  • Osmosis: Diffusion of water through a semi-permeable membrane.
  • Active Transport: Movement against a concentration gradient using energy.

Genetics and Mitosis

  • DNA and Chromosomes:
    • Diploid Cells: 23 pairs of chromosomes.
    • Gametes: Haploid cells (23 chromosomes).
  • Cell Division: Mitosis results in two identical cells.
  • Stem Cells: Unspecialized, can develop into different cell types.

Nervous System

  • Components:
    • CNS: Central nervous system (brain and spinal cord).
    • PNS: Peripheral nervous system (nerves).
  • Reflexes: Fast, involuntary responses bypassing the brain.

Eye Structure and Function

  • Focusing: Accommodation changes lens shape.
  • Retina: Contains rods (light intensity) and cones (color detection).
  • Vision Problems:
    • Myopia: Short-sightedness.
    • Hyperopia: Long-sightedness.

Reproduction and Inheritance

  • Sexual vs. Asexual Reproduction: Genetic variation vs. identical offspring.
  • Genes and Alleles: Dominant vs. recessive traits.
  • Human Genome: Understanding genetic disorders and traits.

Evolution and Natural Selection

  • Darwin’s Theory: Survival of the fittest.
  • Lamarck’s Theory: Adaptation to environment (epigenetics).

Health and Disease

  • Non-communicable Diseases: CVD, diabetes, cancer.
  • Pathogens: Bacteria, viruses, fungi, and protists causing diseases.

Immunity and Vaccination

  • Immune System: Lymphocytes produce antibodies and antitoxins.
  • Vaccination: Exposure to antigens to develop immunity.

Biotechnology and Genetic Engineering

  • Genetic Modification: Inserting genes for desired traits (e.g., insulin production).
  • Fossils: Evidence of past life, mineralized remains.

Practical Applications

  • Food Tests: Identifying nutrients.
  • Osmosis Experiments: Measuring mass change in plant tissues.
  • Bacterial Culturing: Studying antibiotic effects.

Important Concepts for Triple Science Only

  • Epigenetics: Gene expression regulation.
  • Monoclonal Antibodies: Use in treatments and diagnostics.

These notes outline the key concepts and practical applications covered in the EDXL GCSE Biology Paper One. Understanding these core principles is essential for preparing for exams in this subject.

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