How do organisms breathe?
Accordingly, do all organisms breathe through lungs?
All vertebrate animals that live on land have lungs. Frogs and toads have lungs, but when they are in water they can also breathe through their skin. Some animals don't have lungs - fish are the obvious examples.
Beside this, why do animals need to breathe in oxygen?
Animals need oxygen (O) to survive. In fact, all organisms need oxygen to complete the process to burning glucose for fuel. It's purpose is to bring oxygen into your body. One of the products of cellular respiration is carbon dioxide.
Humans have two lungs, a right lung and a left lung. They are situated within the thoracic cavity of the chest. The right lung is bigger than the left, which shares space in the chest with the heart.