The releasing on oxygen is essential for animals to breathe.
Answer:
Either the Chloroplasts or the cell wall
Explanation:
Animals contribute water vapor back into the atmosphere by respiring, breathing out water vapors that rise to the atmosphere. They're perspire to prevent overheating; during this process, water is excreted through the pores and evaporates off the skin, cooling the animal by absorbing the external heat.
That would be the Endoplasmic Reticulum my good friend hope this helped... :D