The sharp increase in respiration rate during fruit ripening promoted by ethylene is termed as:

Correct Option

The correct option is Respiratory climacteric

Explanation

Fruit ripening is a physiological process often regulated by the plant hormone ethylene. In a specific category of fruits, this process is characterized by a distinct physiological event involving a dramatic alteration in metabolic activity.

Option Analysis

• Respiratory climacteric Resp This term specifically defines the sharp increase in the rate of respiration (measured by CO₂ evolution) that occurs during the ripening of climacteric fruits (e.g., apples, bananas, tomatoes). This respiratory spike is stimulated by the hormone ethylene and is essential for the rapid changes associated with ripening, such as color change and softening.
• Photorespiration Photorespiration: Incorrect. Photorespiration is a light-dependent process occurring in C3 plants where the enzyme RuBisCO binds with oxygen instead of carbon dioxide. It is a wasteful metabolic pathway that reduces photosynthetic efficiency and is unrelated to the fruit ripening process.
• Pasteur effect Pasteur effect: Incorrect. The Pasteur effect refers to the inhibition of anaerobic fermentation (glycolysis) by the presence of oxygen. It explains the shift from anaerobic to aerobic respiration, typically observed in yeast and facultative anaerobes, and does not describe fruit ripening.
• Dark respiration Dark respiration: Incorrect. Dark respiration refers to normal cellular respiration that occurs in mitochondria independent of light. While the climacteric rise is a form of respiration, "dark respiration" is a general term for the metabolic process, whereas "respiratory climacteric" specifically denotes the surge in rate induced by ethylene.

Key Takeaway

Respiratory climacteric is the phenomenon of a sudden rise in respiration rate triggered by ethylene during the ripening of specific fruits known as climacteric fruits.