CAIE IGCSE Biology 2 Organisation of the Organism
Practise identifying cell structures, linking specialised features to functions and calculating specimen size or magnification.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Practise identifying cell structures, linking specialised features to functions and calculating specimen size or magnification.
Fig. 6.1 shows some cells from the shoot tip of an onion, Allium cepa.

Fig. 6.1
State the evidence visible in Fig. 6.1 that identifies the cells of A. cepa as plant cells.
cell wall ;
cells are a regular shape / described ;
vacuole(s) ;
AVP ;
Bacteria are useful in biotechnology and genetic engineering.
Fig. 6.1 shows a photomicrograph of a bacterium.

Fig. 6.1
Write the formula that would be used to calculate the actual width of the bacterium.
image size ÷ magnification ;
The actual width of the bacterium is 0.0008 mm .
Convert this value to micrometres (μm).
. μm
0.8(μ m);
State two cell structures found in both animal and bacterial cells.
1
2
any two from:
cell membrane ;
cytoplasm ;
ribosomes ;
DNA ;
The diagram shows a magnified image of a human liver cell with a mitochondrion labelled. The actual size of the liver cell is 20μ m.
The image size of the liver cell is 40 mm and the image size of the mitochondrion is 4 mm .

What is the actual size of the mitochondrion shown in the diagram?
0.002 mm
0.02 mm
0.2 mm
2 mm
A