Photorespiration occurs                   . a. under hot and dry conditions; b. when oxygen is incorporated in the first step of the light-independent reactions; c. when carbon dioxide levels are high inside the plant; d. A and B are correct; e. A, B, and C are correct

Key Concepts

Photorespiration

Photorespiration is a metabolic process in plants that occurs when the enzyme RuBisCO fixes oxygen instead of carbon dioxide, leading to a wasteful pathway that reduces the efficiency of photosynthesis. This process is more likely to happen under conditions of high temperature and low carbon dioxide availability, which can occur during hot and dry weather.

Light-Independent Reactions

The light-independent reactions, also known as the Calvin cycle, are a series of biochemical reactions that occur in the stroma of chloroplasts, where carbon dioxide is fixed into organic molecules. While these reactions primarily utilize carbon dioxide, photorespiration can occur when oxygen is mistakenly incorporated, leading to a decrease in the overall yield of glucose.

Environmental Conditions Affecting Photosynthesis

Environmental factors such as temperature, humidity, and carbon dioxide concentration significantly influence the rate of photosynthesis and the occurrence of photorespiration. Under hot and dry conditions, stomata close to conserve water, which can lead to increased oxygen levels inside the leaf and a higher likelihood of photorespiration occurring.