(a)[2]
Explain why cell A in Fig. 6.1 responds to EGF, whereas cell B does not.
(b)[1]
More mRNA is made in the $G_1$ phase than in mitosis. Suggest why this is the case.
(c)[3]
DNA is copied during the S phase of the cell cycle. EGF is one of several factors that stimulate the transition from the $G_1$ phase to the S phase. State the substances used to make DNA during the S phase.
(d(i))[2]
Fig. 6.2 shows chromosome 1 from rice, $Oryza\ sativa$, during metaphase of mitosis. State the name and the function of the chromosome region labelled X.
(d(ii))[2]
In the cell outline below, draw the chromosome from Fig. 6.2 as it would look in anaphase of mitosis.