Practical Investigation Reference¶
This page gathers the practical patterns that recur across the course. The investigations remain distributed across the topic pages, but this reference keeps the method logic, measurement habits and raw practical-note support in one place.
Role In This Wiki¶
- Gather the practical investigations that are distributed across the course.
- Track common method choices, variables, controls, measurements, graphing habits and evaluation patterns.
- Bridge the topic pages to the raw practical-skills note bundle stored under
raw/web/pmt/notes/Edexcel-IGCSE/Practical-Skills/.
Investigation Map¶
| Topic page | Specification practicals | Main investigation focus | Useful measurements or observations | Raw practical-note support |
|---|---|---|---|---|
| 2c Biological Molecules | 2.9, 2.12, 2.14B |
food tests plus enzyme activity against temperature and pH | colour change, time to end-point, controlled water-bath or buffer conditions | 01. Food Tests.pdf, 02. Enzymes and Temperature.pdf, 03. Enzymes and pH.pdf |
| 2d Movement of Substances into and out of Cells | 2.17 |
diffusion and osmosis in living and non-living systems | mass change, concentration, time, consistent blotting and sample size | 04. Diffusion and Osmosis.pdf |
| 2e Nutrition | 2.23, 2.33B |
photosynthesis requirements and energy content of food | oxygen release, starch test results, temperature rise and mass of food burnt | 05. Photosynthesis.pdf, 06. Energy Content of Food.pdf |
| 2f Respiration | 2.39 |
respiring organisms releasing carbon dioxide and heat | indicator change, temperature change, bubble count or time under controlled conditions | 07. Respiring Seeds.pdf, 14. Anaerobic Respiration.pdf |
| 2g Gas Exchange | 2.45B, 2.50 |
net gas exchange in plants and breathing in humans | indicator colour, breathing rate, carbon dioxide output and effect of exercise | 08. Gas Exchange in Plants.pdf, 09. Breathing in Humans.pdf |
| 2h Transport | 2.58B |
environmental factors affecting transpiration | distance moved by bubble, time, and controlled humidity, wind, light or temperature | 10. Transpiration.pdf |
| 3a Reproduction | 3.5 |
conditions needed for seed germination | germination success across controlled water, oxygen and temperature conditions | 11. Germination.pdf |
| 4a The Organism in the Environment | 4.2, 4.4B |
population size, organism distribution and biodiversity using quadrats | counts, percentage cover, sample number and random or transect placement | 12. Estimating Population Size.pdf, 13. Distribution and Biodiversity.pdf |
Recurring Method Patterns¶
- Keep one independent variable changing at a time and state the dependent variable clearly before collecting data.
- Standardise sample size, starting mass, volume, time and temperature whenever those factors could change the outcome.
- Use repeats and averages to improve reliability, especially in ecology sampling and rate-based practicals.
- Distinguish qualitative observations such as colour change from quantitative measurements such as mass, bubble count or temperature rise.
- When evaluating a method, look first for uncontrolled variables, inconsistent measurements and weak repeat structure before suggesting improvements.