Solution:
The atmosphere is not an organ for taking in oxygen.The atmosphere can be defined as the layer of gases which surrounds the Earth as a blanket. The atmosphere is a mixture of a number of different gases, including oxygen, which is vital for the survival of all living beings on Earth. Oxygen is taken in and utilised by all organisms through the process of respiration. Organs used for taking in oxygen are lungs, gills, stomata, etc. Humans and animals breathe through their lungs. The aquatic animals breathe through gills. Plants breathe or take in oxygen through the stomata.
