A person whose blood can be donated to all other people, must have the blood group
A. O
B. AB
C. B
D. A
Correct Answer:A
Explanation
The correct option is A. O.
Detailed Explanation:
Understanding Blood Groups:
Human blood is classified into different groups based on the presence or absence of specific antigens on the surface of red blood cells. The main blood group systems are the ABO system and the Rh factor.
The ABO blood group system has four main types: A, B, AB, and O.
Type A has A antigens on the surface of red blood cells and anti-B antibodies in the plasma.
Type B has B antigens and anti-A antibodies.
Type AB has both A and B antigens and no anti-A or anti-B antibodies (universal recipient).
Type O has no A or B antigens and has both anti-A and anti-B antibodies (universal donor).
Universal Donor:
A person with blood type O is considered a universal donor because their red blood cells do not have A or B antigens. This means that when type O blood is transfused into a person with any other blood type (A, B, AB), there will be no immune reaction against the transfused blood.
In contrast, if a person with type A blood receives type B blood, their anti-B antibodies will attack the B antigens, leading to a potentially life-threatening reaction.
Why Other Options Are Incorrect:
B. AB: While AB blood type is known as the universal recipient (they can receive blood from any type), they cannot donate blood to everyone. They have both A and B antigens, so if they donate to a person with type A, B, or O blood, the recipient's immune system will recognize the foreign antigens and may mount an immune response.
C. B: Type B blood has B antigens and anti-A antibodies. Therefore, it can only be donated to individuals with type B or AB blood. It cannot be given to type A or O individuals without causing an immune reaction.
D. A: Similar to type B, type A blood has A antigens and anti-B antibodies. It can only be donated to individuals with type A or AB blood, making it unsuitable for universal donation.
Summary of Key Points:
Type O blood is the universal donor because it lacks A and B antigens, preventing immune reactions in recipients.
Type AB blood is the universal recipient but cannot donate to all blood types.
Type A and B blood can only donate to their respective types and AB, but not universally.
Understanding blood group compatibility is crucial for safe blood transfusions.
Revision Summary:
Universal Donor: Type O blood can be given to anyone.
Universal Recipient: Type AB blood can receive from anyone but cannot donate universally.
Compatibility: A and B blood types have specific donation limitations due to the presence of antibodies.
Importance: Knowledge of blood types is essential for safe medical practices, especially in transfusions.