b) Naturally the loss of blood from the system has to be minimized. In addition, leakage would lead to a loss of pressure which would reduce the efficiency of the pumping system. To avoid this, the blood has platelet cells which circulate around the body and plug these leaks by helping to clot the blood at these points of injury.
c) Haemoglobin is the respiratory pigment is found in red blood corpuscles present in human blood.