One of the major functions of erythrocytes (also known as red blood cells) is to carry blood gases such as oxygen and carbon dioxide around the body. Red blood cells contain the pigment haemoglobin which binds to oxygen and carries it around the body, releasing it and allowing the process of aerobic respiration.
The answer is D. Identity of an element is determined by the number of protons, also called the Atomic Number. On the periodic table the atomic number is found above the element name. If you take away or add a proton, the element is not the same element anymore
Nephron helps the urinary system to rid off metabolic waste in our system.