हमारे Blood group अलग - अलग क्यों होते हैं? || Golden blood इतना Rare क्यों होता है?🤔🤔 || 2021 ||

हमारे Blood group अलग - अलग क्यों होते हैं? || Golden blood इतना Rare क्यों होता है?🤔🤔 || 2021 || Why all humans have different blood group system. Who found the humans have different blood groups. What is antigen which is found on the surface on blood cells. What is rh null blood why this is called to golden blood and why is this blood group rare.