(a)[2]
On Fig. 1.1, use label lines and letters to identify each of the following parts: X - xylem tissue P - palisade mesophyll tissue.
(b)[2]
The leaves of C. sinensis have a large surface area and are thin. Explain how each of these two features helps the leaf carry out photosynthesis.
(c(i))[1]
The lower epidermis contains stomata. State one structural difference between a guard cell and other cells of the lower epidermis.
(c(ii))[3]
Abscisic acid plays an important role in closing a stoma. It causes potassium ions to leave guard cells. Outline how the loss of potassium ions from guard cells leads to closure of the stoma.