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The ABO blood group classification is based on antigens on red blood cells and antibodies found in blood plasma.</span>Blood type A has antigen A on the red blood cells and anti - B antibodies in the blood.Blood type B has antigen B on the red blood cells and anti - A antibodies in the blood.Blood type AB has both antigen A and B on the red blood cells but has no anti-A nor anti - B antibodies in the blood<span>Blood type O has no antigen on the red blood cells and has both anti -A and anti B antibodies in the blood.</span>
To help the nervous system and brain develop.
Answer:
Due to the earth's rotation and the gravitational pull of the moon.