Which of the following statements are correct for effect of Carbon dioxide concentration on photosynthesis?

(i) Increase in concentration up to 0.05 per cent can cause an increase in CO 2 fixation rate; beyond this the levels can become damaging over longer periods

(ii) The C 2 and C 4 plants respond differently to CO 2 concentrations

(iii) At low light conditions neither C 3 nor C 4 responds to high CO 2 conditions

(iv) At high light intensities, both C 3 and C 4 plants show increase in the rates of photosynthesis

(v) C 4 plants show saturation at about 360 µlL -1 while C 3 responds to increased CO 2 concentration and saturation is seen only beyond 450 µlL -1

(vi) Current availability of CO 2 levels in atmosphere is limiting to the C 3 plants