The red blood corpuscles have a pigment called hemoglobin that binds to the oxygen and carries it to the whole body in both the conditions, when the body is at rest or when the body is exercising. The oxygenated blood from the heart is carried to the various parts of the body and the de-oxygenated blood from various parts of the body is carried to the lungs where the exchange of gases takes place.
Which one do you need help on
D looks like the oldest one because there is barley anything there. if not then I would do b
Ageing is the word that describes all that change as the organism evolve and it also includes growth !
