true a person's intellectual abilities and temperament are influenced by heredity
O blood is in higher demand because it is the universal donor. People with O blood can donate red blood cells to people with blood types O, A, B, and AB.
While people with type A blood can only donate to people with type A blood and people with type AB blood. People with type B blood can donate only to other people with type B blood and people with type AB blood. People with type AB blood can only donate to people with type AB blood.
