(a)[2]
Identify the structures labelled A and give their function in the cell.
(b)[2]
Cell B contains many mitochondria. Suggest why cell B has a large number of mitochondria.
(c)[2]
Calculate the actual length of the nucleus C. Include your working and give your answer to the nearest $0.1$ micrometre.
(d)[3]
There are many goblet cells in the epithelium lining the trachea and the bronchi in the gas exchange system. Describe the function of goblet cells in the gas exchange system.
(e)[2]
State two differences between the cells lining the alveoli in the lungs and cell B shown in Fig. 1.1.