IGCSE Biology Exam Success Tips

General Strategy

• Learn every fact on the course.
• Understand those facts.
• Learn and apply skills.
• Exam prep can significantly boost success.
• Focus on common question types.

Common Question Types

• The following are based on Paper 1B of the Pearson Edexcel GCSE 9 to 1 specification.

1. Movement of Substances

• Diffusion: Movement of particles from high to low concentration.
  • Mistake: Using "substance" instead of "particle".
• Osmosis: Movement of water from dilute to concentrated solution through a partially permeable membrane.
  • Mistake: Not specifically stating "water".
• Active Transport: Movement from low to high concentration using energy from respiration.

2. Comparing Arteries and Veins

• Arteries: Thicker walls, more elastic tissue, smaller lumen, no valves.
• Veins: Have valves.
• Use comparative language (e.g., thicker, smaller).

3. Gas Exchange System

• Alveoli: Large surface area, one cell thick walls, moist, capillary walls one cell thick, and blood flow maintains concentration gradient.
• Mistake: Saying "alveoli are one cell thick".

4. Absorption in the Small Intestine

• Villi: Large surface area, thin walls, many capillaries, lacteals for absorbing fatty acids and glycerol.
• Mistake: Saying "villi are one cell thick".

5. Genetically Modified Bacteria

• Process: Isolate plasmids, use specific restriction enzyme, extract human gene, join with plasmid using ligase, insert into bacteria.

6. Designing an Investigation

• COMMS acronym:
  • C: Change (Independent variable)
  • O: Organism (Sample)
  • M: Measure (Dependent variable)
  • S: Same/Constant (Controlled variables)
• Example: Effect of light color on fruit production.

7. Stating Variables

• Dependent Variable: What you measure.
• Independent Variable: What you change.
• Control Variables: What you keep constant (e.g., light intensity, temperature).
• Avoid vague terms like "amount".

8. Reliability of Results

• Repetitions and consistency: Mention repeats and controlled conditions.
• Example: Three test tubes per sample and same volume of food sample.

9. Graphing Skills

• Line Graphs: Follow SAPLUK for scale, axes, points, line, units, key.
  • Axes: Independent variable on bottom, dependent on side.
  • Plot with neat X, use ruler for lines.
  • Include units and a key if multiple datasets.
• Bar Graphs: Similar steps but omit key if only one dataset.
  • Consider scale to avoid unnecessary zero point.