This diagram covers Size Calculations within Microscopy for GCSE Biology. Light and electron microscopes, magnification and resolution calculations, specimen preparation, staining techniques, and practical microscopy skills It is section 5 of 19 in this topic. Focus on the labels, the relationships between parts, and the explanation that turns the diagram into an exam-ready answer.
Topic position
Section 5 of 19
Practice
18 questions
Recall
20 flashcards
📏 Size Calculations
The Triangle Method:
I
A
×
M
- I = Image size (what you measure)
- A = Actual size (real size)
- M = Magnification
Key Formulas:
Magnification = Image Size ÷ Actual Size
Actual Size = Image Size ÷ Magnification
Image Size = Actual Size × Magnification
Worked Example:
Question: A cell appears 30mm long under ×400 magnification. What is its actual size?
Solution:
- Image size = 30 mm
- Magnification = ×400
- Actual size = Image size ÷ Magnification
- Actual size = 30 mm ÷ 400 = 0.075 mm
- Convert to micrometers: 0.075 mm × 1000 = 75 μm