Cell BiologyTopic Summary
Topic Summary: Practical Investigations in Cell Biology
Part of Cell Biology Practical Investigations — GCSE Biology
This topic summary covers Topic Summary: Practical Investigations in Cell Biology within Cell Biology Practical Investigations for GCSE Biology. Comprehensive practical skills, experimental design, data analysis, microscopy techniques, and scientific methodology in cell biology It is section 17 of 17 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 17 of 17
Practice
20 questions
Recall
20 flashcards
Topic Summary: Practical Investigations in Cell Biology
Key Terms
- Magnification: Image size ÷ Real size
- Resolution: Ability to distinguish two nearby points
- Iodine: Stains starch/cell walls dark blue-black
- Methylene blue: Stains nuclei blue
- Eyepiece graticule: Scale in eyepiece for measuring cells
- Stage micrometer: Calibration slide for graticule
Must-Know Formulas
MIR Triangle:
- M = I ÷ R (Magnification)
- I = M × R (Image size)
- R = I ÷ M (Real size)
Unit conversion: 1 mm = 1000 µm
% change in mass: ((Final - Initial) ÷ Initial) × 100
Three Required Practicals
| Practical | Key Skill | Key Variable |
|---|---|---|
| RPA1: Microscopy | Focusing, drawing, measuring | Magnification |
| RPA2: Mitosis | Slide prep, staining, identifying phases | Stain concentration |
| RPA3: Osmosis | % change in mass, graphing | Sucrose concentration |
Light vs Electron Microscope
| Feature | Light | Electron |
|---|---|---|
| Maximum magnification | ~x1500 | ~x2,000,000 |
| Resolution | ~200 nm | ~0.2 nm |
| Living specimens | Yes | No |
| Colour images | Yes | No (false colour added) |
| Cost | Low | Very high |