A scaled outline of a cell is shown - HSC - SSCE Biology - Question 10 - 2010 - Paper 1

To determine the diameter of the cell, we note that the diagram shows a circle where a line segment of 5 µm represents the radius. The formula for the diameter of a circle is given by:

$d = 2r$

where $r$ is the radius. Given that the radius is 5 µm, we can calculate:

$d = 2 \times 5 \mu m = 10 \mu m$

Thus, the diameter of the cell is 10 µm.