(a(i))[1]
State the visible feature in Fig. 6.1 that shows the cells of A. cepa are plant cells.
(a(ii))[1]
State the purpose of mitosis in a shoot tip.
(b)[3]
Explain why mitochondria are important in cells that are dividing.
(c(i))[1]
State the name of the plant hormone responsible for cell elongation in stems.
(c(ii))[4]
Explain how the gravitational response of stems is controlled.
(d)[3]
Explain why it is important that only some genes in cell A are expressed in these cells.