Question

what would have happed if c-4 plants did not have kranz anatomy ​

Answer 1

Kranz anatomy in c-4 plants

Explanation:

Its photosynthetic response to varying CO2 and O2 is typical of C4 plants having Kranz anatomy. Lack of night-time CO2 fixation indicates it is not acquiring carbon by Crassulacean acid metabolism. Phosphoenolpyruvate carboxylase, a cytosolic C4 cycle enzyme, is enriched in the peripheral cytoplasm.

When the CO2 level is very low, normal enzymes inside the stroma of plastid {C3 plants} (RUBISCO) start absorbing oxygen instead of CO2. (Photorespiration loss).

To overcome this, sugarcane, maize (C4 plants) have 2 types of plastids.  The plastid present near epidermis only absorbs CO2 (even if it’s % very low) by converting it into 4C compounds (Oxaloacetic acid, malic acid, etc.) and transported into cells around the vascular bundle (Bundle sheath cells =Kranz Anatomy).

In these cells, a special type of plastid with only stromal elements present. Now, good %of CO2 already reached these cells, so RUBISCO can do normal Calvin cycle and form Glucose.

So, C4 plants evolve to overcome the problem related to RUBISCO and overcome photo-respiratory loss by making Kranz Anatomy.