Specialised Cells & Magnification
Interactive lessonScaffoldedExam practice
Syllabus alignment: official course/syllabus source.
Learning targets
- Identify adaptations of specialised animal and plant cells and link structure to function.
- Use magnification = image size ÷ actual size and convert units accurately.
- Interpret unfamiliar cell images using IGCSE command words.
1 · Retrieve: structure → function
Red blood cell
Biconcave shape increases surface area; no nucleus leaves more space for haemoglobin.
Root hair cell
Long extension increases surface area for water and mineral ion uptake.
Ciliated cell
Cilia move mucus; many mitochondria support active movement.
Palisade cell
Many chloroplasts maximise light absorption.
2 · Magnification method
Equation: magnification = image size ÷ actual size.
- Measure the image.
- Convert both values to the same unit.
- Divide image size by actual size.
- State magnification with × and no unit.
1 mm = 1000 μm. A 35 mm image of a 70 μm cell is 35,000 μm ÷ 70 μm = ×500.
Quick check
1. Which feature best increases absorption by a root hair cell?
2. A cell image is 24 mm and actual length is 60 μm. Magnification?
Exam-style practice
Q1. A photomicrograph shows a sperm cell with many mitochondria. Explain how this adaptation supports its function. [2]
Mitochondria release ATP by aerobic respiration; ATP supplies energy for flagellum movement/swimming.
Q2. An image of a cell is 48 mm long. The actual cell is 80 μm. Calculate magnification. [2]