25Schools
Log in Sign up
University revision · Blood Transfusion Science

The ABO Blood Group System

Question 1 of 69 Course: Biomedical Science(Degree)
Q1
What does the term 'serological conflict' or 'ABO discrepancy' refer to?
Choose an answer, then submit to see the explanation.

About this topic

This foundational topic in Blood Transfusion Science details the ABO blood group system, one of the most critical and clinically significant blood group systems. Zambian university and college students will explore its discovery by Landsteiner, the genetics involving genes on chromosome 9, and the resulting genotypes and phenotypes (A, B, AB, O). The biochemistry of ABO antigens, their development, and the characteristics of naturally occurring antibodies (anti-A, anti-B) are covered in depth. Practical laboratory techniques for ABO typing, including forward and reverse grouping using methods like tube testing, gel cards, and automation, are thoroughly explained. The topic also addresses the clinical importance of ABO compatibility in transfusion, highlighting the concepts of universal donors and recipients for red cells and plasma. Learners will study Dutch guidelines for robust typing procedures and investigate common discrepancies and special cases, such as weak subgroups, mixed field reactions, and testing in newborns. This knowledge is vital for Zambian tertiary students pursuing careers in medical laboratories, ensuring safe and accurate pre-transfusion testing.

What you'll practise (50 questions)

  1. The ABO gene is located on which chromosome?
  2. A person with blood group A has which antibodies naturally present in their plasma?
  3. A patient with blood group O can safely receive red cells from which donor group?
  4. What is the most likely cause of a mixed-field agglutination reaction in forward (cell) ABO grouping?
  5. The 'universal plasma donor' is considered to be blood group:
  6. What does the term 'phenotype' refer to in blood group serology?
  7. The 'H antigen' is the precursor substance for A and B antigens. Individuals with the Bombay phenotype lack the H gene. True or False?
  8. What is the significance of a 'rouleaux' formation observed during blood grouping?
  9. In the context of blood grouping, what does the term 'cis-AB' phenotype refer to?
  10. What does a 'mixed field' reaction in a forward blood group typically indicate?
  11. What is the correct statement about blood group AB individuals?
  12. What are naturally occurring antibodies?
  13. What are the expected reactions for blood group B Negative in forward and reverse grouping?
  14. A person with genotype B/O has which phenotype?
  15. What does the term 'universal donor' refer to in the context of red blood cell transfusion?
  16. What does a 'mixed field' reaction in blood grouping typically indicate?
  17. What is the primary role of the 'H antigen' in the ABO blood group system?
  18. True or False: The 'Bombay' phenotype (Oh) results from a lack of the H antigen, preventing the formation of A and B antigens.
  19. True or False: The 'universal plasma donor' is group AB because it lacks both anti-A and anti-B antibodies.
  20. What does the term 'serological conflict' or 'ABO discrepancy' refer to?
  21. Which of the following is a key principle of the ABO blood group system?
  22. Which chromosome carries the ABO gene?
  23. What type of antibody (Ig class) are naturally occurring ABO antibodies primarily?
  24. Anti-A and anti-B antibodies are typically present in newborns at birth.
  25. What is the primary immunoglobulin class of naturally occurring ABO antibodies?
  26. Why is reverse grouping not performed on newborns under three months old?
  27. What is the most frequent ABO blood group in Western Europe?
  28. Which ABO antibody is found in the plasma of a person with blood type B?
  29. What is the approximate percentage of individuals with the A2 subgroup among those with type A blood?
  30. The production of ABO antibodies in infants begins after exposure to intestinal bacteria.
  31. Why is the ABO system of great clinical importance in transfusion medicine?
  32. What does the 'H' antigen refer to in the context of the ABO system?
  33. In which situation is the ABO blood group of a newborn considered 'temporary'?
  34. Which of these is a key feature of ABO antigens on red blood cells?
  35. What is the primary stimulus for the development of 'natural' ABO antibodies?
  36. What is the significance of the 'anti-A1' antibody sometimes found in individuals with the A2 subgroup?
  37. Why might ABO antigens be 'not sufficiently developed' in newborns?
  38. The absence of expected ABO antibodies in an adult's serum is a normal finding.
  39. In the ABO blood group system, what is the biochemical nature of the antigens?
  40. Why are ABO antibodies described as 'naturally occurring'?
  41. What is the approximate number of A or B antigen sites on a single adult red blood cell?
  42. Which of the following is a characteristic of the antibodies in the ABO system?
  43. A blood sample from a 1-month-old infant is sent for ABO typing. The lab performs only forward grouping. Is this sufficient for a definitive result?
  44. What is the role of intestinal bacteria in the ABO system?
  45. What is the significance of the 'H antigen' in the ABO blood group system?
  46. Which of the following describes the correct pairing of ABO blood type with the expected antibodies in plasma?
  47. What does the term 'subgroup' refer to in the context of the ABO system?
  48. The ABO gene directly codes for the A and B antigens on the red cell surface.
  49. What is the clinical implication of an individual having the A2B blood type?
  50. Which of the following populations would you expect to have the highest frequency of the B blood group allele?

Answer each question above to see the correct answer and a full explanation.