Question

The early suggestion that oxygen liberated by plants during photosynthesis comes from water was

• A. proposed by van Niel
• B. confirmed by the use of heavy water
• C. made after the discovery of photorespiration because of Rubisco's sensitivity to oxygen
• D. Was proposed by van Niel and later confirmed by experiments using heavy water

Answer 1

The correct option is D Was proposed by van Niel and later confirmed by experiments using heavy water

van Niel hypothesized that the O2 produced during photosynthesis came from water rather than from carbon dioxide. However this was confirmed by experiments perfomed by Samuel Ruben and Martin Kamen which involved the use of heavy water.