Fat´s structural role is particularly important in the brain, which is 60% fat.
The brain is the fattest organ in our bodies and consist of at least 60% fat.
The respiratory system mainly consists of the lungs. The lungs give oxygen to the body, when you inhale air. They are responsible for removing carbon dioxide from the body. The circulatory system mainly consists of the heart. The heart pumps blood through the body, giving us oxygen. The heart is responsible for pumping blood and creating new blood cells. If we did not have a heart then there would be no blood, therefore, no oxygen. If you think about it, the body's oxygen transport system takes oxygen to the working muscles, through the circulatory and respiratory systems working together. The main workers are the heart, blood and lungs. The whole oxygen transport system works in a cycle.
OK so basically you use a compound light microscope to observe specimen so if you were trying to find micro organisms that would be the one to choose.
