This deep dive covers Required Practical 1: Light Microscopy 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 2 of 18 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Required Practical 1: Light Microscopy
Equipment and Setup
- Light microscope with x4, x10, x40 objective lenses
- Prepared slides (plant cells, animal cells)
- Glass slides and coverslips
- Mounting medium or water
- Ruler or stage micrometer
Method
- Place slide on stage and secure with clips
- Start with lowest magnification (x4 objective)
- Use coarse focus to get approximate focus
- Switch to higher magnifications and use fine focus
- Observe and draw cells, noting key features
- Measure cells using stage micrometer
Microscopy Calculations
Magnification = Image Size ÷ Actual Size
Image Size = Magnification × Actual Size
Actual Size = Image Size ÷ Magnification
Drawing Guidelines
- Use pencil and draw clear, continuous lines
- Draw what you see, not what you know should be there
- Include scale and magnification
- Label clearly with straight lines
- No shading or sketchy lines
Practice questions for Cell Biology Practical Investigations
When using a light microscope to observe cells, which objective lens should be used first?
Describe how to focus a light microscope on a specimen.
Quick recall flashcards
What is the formula for percentage change in mass?
Percentage change = ((Final mass - Initial mass) ÷ Initial mass) × 100
What is the formula for magnification?
Magnification = Image Size ÷ Actual Size