Free Scientist in Blood Banking (BB) Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Scientist in Blood Banking (BB) practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Under 21 CFR 630.10, when must a blood collection establishment ordinarily determine donor eligibility?

   1. A. On the day of donation and before collection
   2. B. When the donor schedules the appointment
   3. C. After collection but before component labeling
   4. D. When the component is released for use

   Answer: A

   Explanation: "You must determine donor eligibility on the day of donation, and before collection." This fixes the ordinary timing. The other choices shift the decision to an earlier appointment or a later processing stage; the limited exceptions in the section do not make those the ordinary rule.

   Reference: 21 CFR § 630.10 General donor eligibility requirements — § 630.10(c)

2. 2Which type of enzyme is encoded by the main A and B alleles of the ABO gene?

   1. A. Glycosyltransferase
   2. B. Glycosidase
   3. C. Protease
   4. D. Lactate dehydrogenase

   Answer: A

   Explanation: "The A and B alleles each encode a glycosyltransferase" A and B encode enzymes that add sugars during antigen synthesis; the other enzymes cleave glycans or proteins or catalyze red-cell metabolism.

   Reference: Blood Groups and Red Cell Antigens — Chapter 5, The ABO blood group, Molecular basis

3. 3Which cell engulfs a red-cell antigen and presents antigenic fragments with MHC class II in the described immune response?

   1. A. Macrophage
   2. B. Platelet
   3. C. Mature red cell
   4. D. Granulocyte

   Answer: A

   Explanation: "When the macrophage encounters an antigen, it engulfs it, digests it, and then presents the antigenic fragments on its cell surface together with MHCII" The macrophage processes and presents antigen. The alternatives do not perform the described MHC II presentation step.

   Reference: Blood Groups and Red Cell Antigens — Chapter 3, Antigen processing

4. 4In ABO forward grouping, what is detected by testing a person's red cells with anti-A and anti-B?

   1. A. A and B antigens on the red cells
   2. B. Anti-A and anti-B in the plasma
   3. C. IgG coating the red cells in vivo
   4. D. Unexpected antibodies in donor serum

   Answer: A

   Explanation: "identify the red blood cell antigens using known anti-A, antiB and anti-A,B reagents (red blood cell or forward group)" Forward grouping identifies the antigens on the tested cells; reverse grouping addresses plasma antibodies.

   Reference: PK SYSTEM Reagent Red Blood Cells (A1 and B) Instructions for Use — Summary and Explanation, page 1

5. 5A patient has a symptomatic deficit of oxygen-carrying capacity despite physiologic compensation. Which component addresses that deficit directly?

   1. A. Fresh frozen plasma
   2. B. Red blood cells
   3. C. Cryoprecipitated AHF
   4. D. Platelets

   Answer: B

   Explanation: "Red-cell-containing components are indicated for treatment of symptomatic or critical deficit of oxygen-carrying capacity." Red cells add circulating hemoglobin and are indicated for this deficit.

   Reference: Circular of Information for the Use of Human Blood and Blood Components — Red Blood Cell Components, Indications, page 11

6. 6How should CLIA proficiency-testing samples be processed relative to patient specimens?

   1. A. On a separate method designed only for PT
   2. B. Using the same method and number of tests as patient specimens
   3. C. By referral to another laboratory before reporting
   4. D. Only after the laboratory sees the expected result

   Answer: B

   Explanation: "Must be tested the same way and the same number of times as testing patient specimens." PT must reflect the ordinary patient testing process.

   Reference: CLIA Proficiency Testing Program Requirements: General and Cytology — General Proficiency Testing, PT sample handling

7. 7Which precollection action is expressly part of determining a donor's eligibility under 21 CFR 630.10(d)?

   1. A. Relying only on the donor's previous eligibility record
   2. B. Assessing the donor's medical history
   3. C. Deferring the donor's physical assessment until after donation
   4. D. Using infectious disease test results as the sole eligibility check

   Answer: B

   Explanation: "Assess the donor's medical history;" Medical history assessment is one required precollection procedure. The other choices replace or defer elements the regulation requires.

   Reference: 21 CFR § 630.10 General donor eligibility requirements — § 630.10(d)(3)

8. 8What molecular effect does the main O allele have on its H-antigen precursor?

   1. A. It leaves the H precursor unmodified
   2. B. It converts H into A antigen
   3. C. It converts H into B antigen
   4. D. It removes H from the cell surface

   Answer: A

   Explanation: "The O allele encodes an inactive glycosyltransferase that leaves the ABO antigen precursor (the H antigen) unmodified." The inactive O transferase does not add the A or B defining sugar. The alternatives describe active modification or removal.

   Reference: Blood Groups and Red Cell Antigens — Chapter 5, The ABO blood group, Molecular basis

9. 9After antigen presentation by a macrophage, which lymphocyte type binds the antigen-MHC II complex?

   1. A. T helper cell
   2. B. Cytotoxic T cell
   3. C. B lymphocyte
   4. D. Natural killer cell

   Answer: A

   Explanation: "A T helper cell binds to the antigen/MHCII on the macrophage" T helper cells recognize the presented complex; the other cells do not have this role.

   Reference: Blood Groups and Red Cell Antigens — Chapter 3, Antigen processing

10. 10What specimen and reagent cells are paired for ABO reverse grouping?

    1. A. Patient red cells with anti-A and anti-B
    2. B. Patient plasma with known A1 and B red cells
    3. C. Donor red cells with patient plasma
    4. D. Patient red cells with antiglobulin reagent

    Answer: B

    Explanation: "verifying the presence of the corresponding antibodies in the plasma by using known red blood cells A1 and B (plasma or reverse group)." The plasma is tested against known A1 and B cells to detect expected ABO antibodies.

    Reference: PK SYSTEM Reagent Red Blood Cells (A1 and B) Instructions for Use — Summary and Explanation, page 1