Which chemical accelerates the ripening of fruit and hastens the wilting of flowers?

• A. Carbon dioxide
• B. Ethylene
• C. Nitrogen
• D. Oxygen

Answer: (B)

Ethylene is a gaseous plant hormone that regulates aging and ripening. It is produced by fruits as they mature and acts as a signal to trigger the biochemical changes of ripening—softening, color change, and aroma development. It also promotes senescence in flowers, hastening wilting and eventual drop. Because it serves this signaling role to accelerate aging and ripening, it fits the description in the question. The other gases don’t function as ripening signals: carbon dioxide is mainly a byproduct and can influence storage atmospheres but doesn’t drive ripening; nitrogen is inert and not a signaling molecule; oxygen supports respiration but does not trigger ripening or wilting processes.