What led to the evolution of C4 pathway of photosynthesis ? Describe in detail

(a) The C4 plants are sugarcane, maize, Amaranthus, grasses etc. The photorespiration is a wasteful process. It is avoided by these C4 plants.
(b) It needs mesophyll cells and bundle sheath cells. The bundle sheath show Kranz anatomy. The C4 plants have dimorphic chloroplasts. In mesophyll cells, chloroplast are granal (have thylakoids) but in bundle sheath cells, chloroplasts are agranal (grana are absent in thylakoids are found in stroma lamellae).
© In these plants, light reaction occurs in the mesophyll cells but C02 is fixed in bundle sheath cells.
(d) Rubisco is present in bundle sheath cells only. So
oxygenation of RuBP is avoided. These plants have C02 concentrating mechanism.