ABO Blood Groups and Transfusion — NEET Biology
📚 Practice ConceptABO grouping is based on the presence or absence of two surface antigens (chemicals that can induce immune response) on the RBCs namely A and B. Similarly, the plasma of different individuals contain two natural antibodies (proteins produced in response to antigens). The distribution of antigens and antibodies in the four groups of blood, A, B, AB and O are given in Table 15.1. You probably know that during blood transfusion, any blood cannot be used; the blood of a donor has to be carefully matched with the blood of a recipient before any blood transfusion to avoid severe problems of clumping (destruction of RBC). The donor's compatibility is also shown in the Table 15.1.
Which of the following statements about ABO and Rh blood grouping systems and their compatibility are correct? S1: Blood group A individuals possess anti-B antibodies in their plasma and A antigens on their RBCs. S2: A person with blood group O is considered a universal donor because their plasma contains anti-A and anti-B antibodies, and their RBCs lack both A and B antigens. S3: Individuals with blood group AB are known as universal recipients primarily due to the presence of both A and B antigens on their RBCs. S4: Rh incompatibility leading to erythroblastosis foetalis can occur when an Rh-negative mother carries an Rh-positive foetus, typically affecting the second or subsequent Rh-positive pregnancies. S5: The Rh antigen is observed on the surface of RBCs in nearly 20% of humans, categorizing them as Rh-positive.
View solution & NCERT explanation
Correct answer: B — S1, S2, and S4
Let's evaluate each statement based on NCERT text: S1: According to Table 15.1, individuals with blood group A have A antigens on their RBCs and anti-B antibodies in their plasma. This statement is correct. S2: Group 'O' blood can be donated to persons with any other blood group and hence 'O' group individuals are called 'universal donors'. Table 15.1 shows group O has no antigens on RBCs and anti-A, B antibodies in plasma. This statement is correct. S3: Persons with 'AB' group can accept blood from persons with AB as well as the other groups of blood. Therefore, such persons are called 'universal recipients'. This is due to the *absence* of anti-A and anti-B antibodies in their plasma, not primarily due to the presence of antigens on their RBCs (which would cause a reaction from donor antibodies). While they do have A and B antigens, the universal recipient property comes from lacking antibodies. This statement is incorrect as it misattributes the primary reason. S4: Rh incompatibility (mismatching) has been observed between the Rh-ve blood of a pregnant mother with Rh+ve blood of the foetus. During the delivery of the first child, the mother starts preparing antibodies, and in subsequent pregnancies, these antibodies can destroy foetal RBCs. This condition is called erythroblastosis foetalis. This statement is correct. S5: The Rh antigen is observed on the surface of RBCs of majority (nearly 80 per cent) of humans, who are called Rh positive (Rh+ve). Therefore, stating 20% of humans are Rh-positive is incorrect; 80% are Rh-positive, and 20% are Rh-negative. This statement is incorrect. Therefore, statements S1, S2, and S4 are correct. Option A is incorrect because S3 is incorrect. Option B is correct because S1, S2, and S4 are correct. Option C is incorrect because S3 and S5 are incorrect. Option D is incorrect because S3 and S5 are incorrect. The tested concept is the principles of ABO and Rh blood grouping, including antigen-antibody distribution and transfusion compatibility rules.
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