(a)[2]
Calculate the magnification of the electron micrograph shown in Fig. 1.1. Include your working and give the result to the nearest whole number.
(b)[4]
Explain how the cells labelled A and the structures labelled B in Fig. 1.1 help protect the tracheal lining.
(c)[5]
Cells such as C, found at the base of the tracheal epithelium, divide by mitosis. Describe the changes that take place within the cell from the start of prophase to the end of metaphase.