Question

How many cell types does the leaf have that fix co2 in both c3 and c4 cycles ??

Answer 1

C3 cycle (Calvin Cycle) occurs in the mesophyll cells.
C4 cycle is same as that of C3 cycle the difference is that it occurs in two types of cells bundle sheath and mesophyll cells. In this cycle CO₂ is fixed by the molecule phosphoenolpyruvate and product gets converted into malate that is transported to the bundle sheath cell for entering into the calvin cycle.