Give examples of the biological role of chemical elements.

Iron ions are part of the blood, they help transport other elements throughout the body, and when cut, help the blood to clot and give it a red color. Oxygen supports life in the body, because with the help of oxygen, the body breathes and the carbon is removed from it. Calcium is found in bones and helps to form and develop bones in the skeleton. Carbon forms macro and micro molecules, with the help of which the cells of the body are formed. Potassium acts as a catalyst for cell growth. Iodine strengthens the thyroid gland, and hence the immune system.