In a plant, the reactions that produce molecular oxygen (O2) take place in_____. Naim 11:35 AP Biology Chapter 10 In a plant, the reactions that produce molecular oxygen (O2) take place in_____. a. the light reactions and the Calvin Cycle b. neither the light reactions nor the Calvin Cycle c. the light reactions alone d. the Calvin Cycle alone Answer: C Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+