On a hot dry day, a C3 plant experiences high oxygen levels relative to carbon dioxide within the leaf air spaces. Which molecule does RuBP carboxylase combine with RuBP?
Q1. On a hot dry day, a C3 plant experiences high oxygen levels relative to carbon dioxide within the leaf air spaces. Which molecule does RuBP carboxylase combine with RuBP?
Answer: Oxygen
Explanation: Rubisco acts as an oxygenase when oxygen levels are high, initiating photorespiration. Carbon dioxide is the preferred substrate under normal conditions.