A brightly lit leaf is releasing oxygen into the air. What becomes of the rest of the oxygen that the leaf makes?
Explanation
Respiration is running in the very cells that are making this gas, so part of the supply is consumed on the spot and only the surplus diffuses away. Assuming that the whole amount leaves the leaf untouched until dark rests on the belief that the two processes cannot run together, and a leaf has no store where a gas could be kept waiting.