A student counted stomata on the lower epidermis of a leaf using a light microscope. The printed photomicrograph of the field of view has a width of 120 mm and a height of 80 mm. The magnification of the image is ×200\times 200×200. There are exactly 12 stomata visible in this field of view.
Which of the following is the correct stomatal density of this leaf?
50.0 stomata mm−250.0 \text{ stomata mm}^{-2}50.0 stomata mm−2
1.25 stomata mm−21.25 \text{ stomata mm}^{-2}1.25 stomata mm−2
0.00125 stomata mm−20.00125 \text{ stomata mm}^{-2}0.00125 stomata mm−2
250 stomata mm−2250 \text{ stomata mm}^{-2}250 stomata mm−2
34 exam-style questions on OCR A A Level Biology Exchange surfaces. Each one has a worked solution and a mark scheme showing where the marks go.