<span>Oxygen is necessary for respiration but also provides UV radiation protection.Through a layer of oxygen compounds, known as the Ozone layer, UV light from the sun is filtered out. The Ozone layer is made of O3 molecules, which is the combination of three oxygen molecules that have bonded together in a unique way.</span>
Answer: the answer depends on whether you are referring to eukaryotic or prokaryotic.
Explanation:
In eukaryotic cells, it resides in the nucleus, tightly and carefully packed and protected. In prokaryotic cells it floats around in the cytoplasm.
The five levels of organization are tissues, cells , organs, organ systems and organisms .