Blood grouping and Rh factor MCQs With Answer

Blood grouping and Rh factor MCQs With Answer

Understanding blood grouping and Rh factor is essential for B. Pharm students involved in transfusion medicine, clinical pharmacology and patient safety. This concise set of MCQs with answers covers ABO system, Rh antigens, forward and reverse typing, Coombs tests, Rh incompatibility, hemolytic transfusion reactions and Rh immunoprophylaxis. Questions focus on antigens, antibodies, compatibility rules, weak D, hemolytic disease of the newborn, cross-matching, and clinical implications for drug therapy and blood product administration. Emphasis on mechanisms, laboratory interpretation and preventive strategies helps build practical competence for pharmacy practice and hospital settings. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What determines an individual’s ABO blood group?

• The presence or absence of specific red cell antigens (A and B)
• The plasma concentration of hemoglobin
• The secretion of antibodies into saliva only
• The serum potassium level

Correct Answer: The presence or absence of specific red cell antigens (A and B)

Q2. Which antibody class is predominantly responsible for ABO incompatibility reactions?

• IgM
• IgG
• IgA
• IgE

Correct Answer: IgM

Q3. In forward typing, what is being tested?

• Red cell antigens reacting with known antisera
• Patient serum reacting with known red cells
• Compatibility between donor and recipient plasma
• Direct antiglobulin binding on fetal cells

Correct Answer: Red cell antigens reacting with known antisera

Q4. What does the indirect Coombs test detect?

• Free antibodies in patient serum that can bind to red cells
• Antibodies already bound to patient red cells in vivo
• Complement levels in plasma
• Platelet aggregation defects

Correct Answer: Free antibodies in patient serum that can bind to red cells

Q5. Which blood group is considered the universal donor for RBC transfusion?

• O negative
• AB positive
• A negative
• B positive

Correct Answer: O negative

Q6. Which blood group is considered the universal plasma donor?

• AB
• O
• A
• B

Correct Answer: AB

Q7. Rh positive indicates presence of which antigen?

• D antigen
• C antigen only
• E antigen only
• Kell antigen

Correct Answer: D antigen

Q8. What is the clinical significance of weak D testing?

• To identify variant D expression that may affect Rh typing and transfusion decisions
• To determine ABO blood group
• To measure antibody titers for IgM
• To detect platelet antibodies

Correct Answer: To identify variant D expression that may affect Rh typing and transfusion decisions

Q9. Hemolytic disease of the fetus and newborn (HDFN) due to Rh incompatibility is primarily caused by which antibody?

• Maternal IgG anti-D crossing the placenta
• Paternal IgM anti-A crossing the placenta
• Fetal IgM anti-D attacking maternal cells
• Maternal IgA in breast milk

Correct Answer: Maternal IgG anti-D crossing the placenta

Q10. Which prophylactic agent is used to prevent Rh alloimmunization in an Rh-negative mother?

• Anti-D immunoglobulin (RhIg)
• Heparin
• IV iron
• Rho kinase inhibitor

Correct Answer: Anti-D immunoglobulin (RhIg)

Q11. A patient with blood group O will have which naturally occurring antibodies?

• Anti-A and anti-B
• Anti-A only
• Anti-B only
• No anti-A or anti-B

Correct Answer: Anti-A and anti-B

Q12. The direct antiglobulin test (DAT) is primarily used to detect:

• Antibodies or complement bound to patient’s RBCs in vivo
• Free antibodies in serum
• Type and screen compatibility
• Plasma glucose level

Correct Answer: Antibodies or complement bound to patient’s RBCs in vivo

Q13. Which scenario best describes an acute hemolytic transfusion reaction?

• Intravascular hemolysis due to ABO incompatible transfusion causing fever, flank pain and hemoglobinuria
• Delayed antibody-mediated extravascular hemolysis occurring weeks later
• Allergic urticaria from plasma proteins without hemolysis
• Post-transfusion iron overload after multiple transfusions

Correct Answer: Intravascular hemolysis due to ABO incompatible transfusion causing fever, flank pain and hemoglobinuria

Q14. What is the Bombay (Oh) phenotype characterized by?

• Absence of H antigen leading to lack of A and B despite genotype
• Overexpression of H antigen with strong A reactivity
• Only Rh antigen absence
• Exclusive production of IgG anti-B

Correct Answer: Absence of H antigen leading to lack of A and B despite genotype

Q15. Cross-matching before transfusion primarily ensures:

• Compatibility between donor RBCs and recipient serum to prevent hemolysis
• Matching of donor and recipient platelet counts
• Equal hematocrit levels in donor and recipient
• Verification of donor blood pressure

Correct Answer: Compatibility between donor RBCs and recipient serum to prevent hemolysis

Q16. Which antigen system is most commonly implicated in severe HDFN after Rh-D?

• Kell (K) system
• MNS system
• Duffy system

Correct Answer: Kell (K) system

Q17. In reverse typing, what is tested?

• Patient serum for anti-A and anti-B using known reagent A and B cells
• Patient red cells with anti-A and anti-B sera
• Complement activation on red cells
• Platelet function in plasma

Correct Answer: Patient serum for anti-A and anti-B using known reagent A and B cells

Q18. A delayed hemolytic transfusion reaction most often results from:

• An anamnestic IgG response to previously formed alloantibodies
• Immediate IgM mediated ABO incompatibility
• Bacterial contamination of blood unit
• Transfusion-associated circulatory overload

Correct Answer: An anamnestic IgG response to previously formed alloantibodies

Q19. Which laboratory finding supports intravascular hemolysis after a transfusion reaction?

• Hemoglobinuria and elevated plasma free hemoglobin
• Isolated thrombocytopenia only
• Low lactate dehydrogenase with decreased bilirubin
• Decreased reticulocyte count

Correct Answer: Hemoglobinuria and elevated plasma free hemoglobin

Q20. Why is IgG anti-D clinically significant while IgM anti-A/B is not a cause of HDFN?

• IgG crosses the placenta; IgM does not cross placenta effectively
• IgM is more avid at body temperature
• IgG cannot fix complement
• IgM is only produced after birth

Correct Answer: IgG crosses the placenta; IgM does not cross placenta effectively

Q21. What is the principal mechanism of action of administered anti-D immunoglobulin (RhIg)?

• It clears fetal RhD-positive red cells from maternal circulation before sensitization
• It neutralizes maternal IgG anti-D already formed
• It blocks maternal IgM production
• It destroys maternal B cells in the spleen permanently

Correct Answer: It clears fetal RhD-positive red cells from maternal circulation before sensitization

Q22. Which test would you use to detect complement-coated RBCs in vivo?

• Direct antiglobulin test (with anti-C3d)
• Indirect Coombs test only
• Cold agglutinin titer
• Serum protein electrophoresis

Correct Answer: Direct antiglobulin test (with anti-C3d)

Q23. A B. Pharm student should recognize that alloimmunization risk increases with:

• Multiple transfusions from different donors
• First single transfusion in childhood
• Exclusive use of autologous blood
• Strict ABO identical transfusions only

Correct Answer: Multiple transfusions from different donors

Q24. What defines a Type and Screen procedure?

• Determining ABO/Rh and screening patient serum for unexpected antibodies
• Cross-matching a donor unit for immediate transfusion
• Measuring blood glucose and electrolytes before transfusion
• Typing donor HLA antigens only

Correct Answer: Determining ABO/Rh and screening patient serum for unexpected antibodies

Q25. Which antigen is part of the Rh blood group family besides D?

• C
• H
• Bombay antigen
• Lewis a

Correct Answer: C

Q26. What is the main reason to perform an antibody identification panel?

• To determine specificity of unexpected antibodies in patient serum
• To check hematocrit levels
• To identify platelet antigens only
• To quantify IgM vs IgG ratios

Correct Answer: To determine specificity of unexpected antibodies in patient serum

Q27. Which practice reduces the risk of transfusion-transmitted infections?

• Careful donor screening and blood testing for pathogens
• Using older stored blood preferentially
• Mixing plasma units from multiple donors
• Skipping leukoreduction in immunocompromised patients

Correct Answer: Careful donor screening and blood testing for pathogens

Q28. In immunohematology, what is alloantibody?

• An antibody formed against foreign antigens of the same species
• An antibody against self-antigens only
• A non-specific inflammatory protein
• A complement fragment

Correct Answer: An antibody formed against foreign antigens of the same species

Q29. Which component is most appropriate to treat a patient with active hemorrhage to restore oxygen-carrying capacity?

• Packed red blood cells (PRBCs)
• Fresh frozen plasma
• Platelet concentrate
• Cryoprecipitate

Correct Answer: Packed red blood cells (PRBCs)

Q30. What laboratory sign typically increases during hemolysis due to extravascular destruction?

• Indirect (unconjugated) bilirubin
• Decreased haptoglobin with low bilirubin
• Rapid rise in serum creatinine only
• Isolated decreased LDH

Correct Answer: Indirect (unconjugated) bilirubin

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com