Free Medical Laboratory Technician MCQ Questions and Answers — Questions and Answers
Question 1: The amount to which a procedure deviates from a calculated mean value or a known value is referred to as
- Percent deviation
- Standard deviation (Correct answer)
- Coefficient variation
- Quality control
Correct answer: Standard deviation
Standard deviation is a statistical measure that quantifies the amount of variation or dispersion of a set of data values. It indicates how much individual data points typically deviate from the mean (average) value. In laboratory quality control, standard deviation is crucial for assessing the precision and reproducibility of a procedure.
Question 2: The majority of plasma thyroxine (T4) is
- Free
- Bound to cholesterol
- Bound to globulin (Correct answer)
- Bound to albumin
Correct answer: Bound to globulin
The majority of thyroxine (T4) in plasma is transported bound to plasma proteins, primarily thyroid-binding globulin (TBG). While a small fraction is also bound to albumin and transthyretin, TBG has the highest affinity and capacity for T4. Only a very small percentage of T4 circulates as free hormone, which is the biologically active form.
Question 3: For a qualitative VDRL test, inactivated serum is used in a quantity of
- 0.10 mL
- 0.05 mL (Correct answer)
- 0.15 mL
- 0.02 mL
Correct answer: 0.05 mL
For a qualitative VDRL (Venereal Disease Research Laboratory) test, a specific quantity of inactivated serum is required for accurate results. The standard volume used for this test is 0.05 mL. This precise measurement ensures the correct antigen-antibody ratio for flocculation to occur, allowing for the detection of reagin antibodies associated with syphilis.
Question 4: A distribution on one side of the mean of six or more consecutive daily values that maintain a constant level is referred to as a distribution.
- Shift (Correct answer)
- Trend
- Mean deviation curve
- Normal distribution curve
Correct answer: Shift
In quality control, a 'shift' refers to a sudden and sustained change in the mean of a quality control material, where six or more consecutive daily values fall on one side of the established mean. This indicates a systematic error in the analytical process, such as a calibration issue or a change in reagent lot. It requires immediate investigation and corrective action to restore accuracy.
Question 5: Some automated blood cell counters' operating principle is based on the
- Amount of hemoglobin in the red cell
- Value of the cell indices
- Weight of the hemoglobin in the red cell
- Size of the particle being counted (Correct answer)
Correct answer: Size of the particle being counted
Many automated blood cell counters operate on the principle of impedance, which measures changes in electrical resistance as cells pass through an aperture. As a cell passes, it displaces a volume of electrolyte, causing a momentary change in resistance proportional to the cell's size. This allows the instrument to count and size individual cells, such as red blood cells, white blood cells, and platelets.
Question 6: A1 or A2 patients are identified by blood type using
- Anti-A serum
- Anti-AB serum
- Dolichos biflorus serum (Correct answer)
- Anti-A2 serum
Correct answer: Dolichos biflorus serum
To differentiate between A1 and A2 subgroups of the A blood type, Dolichos biflorus lectin (often referred to as Dolichos biflorus serum) is used. This lectin specifically agglutinates A1 red blood cells, but not A2 red blood cells. This reaction helps to identify individuals as either A1 or A2, which can be important in certain transfusion medicine scenarios.
Question 7: Urine can be examined for the presence of _________ to identify metabolic acidosis.
- Protein
- Uric acid
- Ketone bodies (Correct answer)
- Glucose
Correct answer: Ketone bodies
Ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone) are produced when the body metabolizes fat for energy instead of carbohydrates. In conditions like uncontrolled diabetes mellitus (diabetic ketoacidosis) or prolonged starvation, the accumulation of these acidic compounds leads to metabolic acidosis. Their presence in urine, known as ketonuria, is a strong indicator of this metabolic state.
Free Medical Laboratory Technician MCQ Questions and Answers
The amount to which a procedure deviates from a calculated mean value or a known value is referred to as