(a(i))[5]
With reference to Fig. 7.1: name the stage of the Calvin cycle taking place at $A$; name the enzyme involved in the stage of the Calvin cycle taking place at $A$; name two examples of substance $C$; name the biochemical process that produces reduced $\text{NADP}$ and $\text{ATP}$.
(a(ii))[1]
With reference to Fig. 7.1, outline what is taking place at stage $B$ of the Calvin cycle.
(b)[3]
Explain why a tight ring of mesophyll cells surrounds the bundle sheath cells in the leaves of a C4 plant.