Class 11 NEET Biology Photosynthesis in Higher Plants

(d) : The dark reactions or Blackman's reactions or biosynthetic phase involves three steps: (i) Fixation of CO2 , (ii) Reduction of CO2 and (iii) Synthesis of other compound from glucose. It is independent of light. Pigment System I is relatively very weakly fluorescent while pigment system II is strongly fluorescent. Light energy absorbed by pigment in the two systems is ultimately trapped by the P700 and P680 Light reaction is associated with the grana of the chloroplasts. It takes place in the presence of light only.