Many enzymes of photosynthesis, respiration and nitrogen metabolism are activated by

(1) Ca⁺⁺

(2) Zn⁺⁺

(3) Mn⁺⁺

(4) Oxygen

(1) Splitting of water to liberate oxygen

(2) Transfer of electrones through z scheme

(3) Cyclic Phosphorespiration

(4) Photorespiration

(1) Zn++

(2) Cl-

(3) Ca++

(4) Mn+

(1) Cupric form

(2) Cuprous form

(3) CuO

(4) Cu

(1) Cu⁺⁺

(2) Fe⁺⁺

(3) Cu⁺

(4) Cl^-

(1) B

(2) Cl^-

(3) Mo

(4) Cu

(1) Membrane functioning, utilization of Ca++

(2) Pollen germination, uptake of Ca++

(3) Cell elongation, catalase activation

(4) Cell differentiation, carbohydrate translocation

(1) Nitrogenase

(2) Nitrate Reductase

(3) Catalase

(4) Both B and C

(1) Na+

(2) K+

(3) Cl-

(4) Mo++

(1) Cl-

(2) Mn++

(3) Cu

(4) Both A and C