Question 41
In what kind of plants do you come across 'Kranz anatomy'? To which conditions are those plants better adapted? How are these plants better adapted than the plants, which lack this anatomy?
Kranz anatomy refers to the dimorphism in the chloroplast structure. It is found in C4 plants. The cells of leaves have two types of chloroplast in them.
Granal Chloroplast it is found in the mesophyll cells of leaves. Chloroplast have well developed grana in them. These chloroplast effectively fix CO2 even if it is present in lower concentrations. PEP carboxylase is present which fix CO2 and to form oxaloacetic acid (4 carbon compound).
Agranal Chloroplast Present in bundle sheath cells of the leaves. C3 cycle occurs in these cells with the presence of RuBisCo enzyme.
The C4 plants are well adapted to high CO2 concentration in much low thus C4 plants can perform high rate of photosynthesis even the stomata are closed or there is the shortage of water thus, they can conserve water.
Since, PEP-carboxylase is insensitive of O2 thus excess O2 has us inhibitory effect in C4 pathway and there is no photosynthesis in C4 plant.
Thus, C4 plants are better adapted to tropical and desert (hot acid habitats) areas than the plants, that lack this anatomy.