BIOS 251 Lab Practical Exam 1 (Latest
Update ) Anatomy and
Physiology IV with Lab | Questions &
Answers | 100% Correct | Grade A -
Chamberlain
1. Which objective lens is used for high-power observation in a
compound microscope?
A. 4x
B. 10x
C. 40x
D. 100x
Correct answer: C
Rationale: The 40x objective is commonly referred to as high
power; it allows detailed observation of cells.
2. Which microscope part controls the amount of light reaching
the specimen?
A. Coarse adjustment
B. Diaphragm
,C. Ocular lens
D. Stage
Correct answer: B
Rationale: The diaphragm regulates light intensity for optimal
contrast.
3. Which technique is used to separate plasma from whole blood?
A. Filtration
B. Centrifugation
C. Precipitation
D. Diffusion
Correct answer: B
Rationale: Centrifugation separates components based on density,
isolating plasma from cells.
4. Which pipette is most accurate for transferring 1 mL of
solution?
A. Volumetric pipette
B. Graduated pipette
C. Pasteur pipette
D. Micropipette
Correct answer: A
Rationale: Volumetric pipettes are calibrated for precise volume
measurements.
,5. Which stain is used to observe bacterial cell walls?
A. Hematoxylin
B. Gram stain
C. Eosin
D. Methylene blue
Correct answer: B
Rationale: Gram staining differentiates bacteria by cell wall
properties.
6. Which lab instrument measures pH of a solution?
A. Thermometer
B. Spectrophotometer
C. pH meter
D. Centrifuge
Correct answer: C
Rationale: A pH meter provides precise measurement of hydrogen
ion concentration.
7. Which solution is used as a negative control in an enzyme
assay?
A. Substrate only
B. Enzyme only
C. Buffer without enzyme or substrate
D. Enzyme and substrate
, Correct answer: C
Rationale: Negative controls ensure that observed activity is due to
the enzyme.
8. Which structure directs the path of light in a microscope?
A. Objective lens
B. Condenser
C. Stage
D. Ocular lens
Correct answer: B
Rationale: The condenser focuses light onto the specimen for
clarity.
9. Which method is used to determine cell size under a
microscope?
A. Micrometer calibration
B. Centrifugation
C. Spectrophotometry
D. Titration
Correct answer: A
Rationale: Calibration with a stage micrometer allows accurate
measurement of cells.
10. Which lab technique is used to separate mixtures based on
molecular size?
Update ) Anatomy and
Physiology IV with Lab | Questions &
Answers | 100% Correct | Grade A -
Chamberlain
1. Which objective lens is used for high-power observation in a
compound microscope?
A. 4x
B. 10x
C. 40x
D. 100x
Correct answer: C
Rationale: The 40x objective is commonly referred to as high
power; it allows detailed observation of cells.
2. Which microscope part controls the amount of light reaching
the specimen?
A. Coarse adjustment
B. Diaphragm
,C. Ocular lens
D. Stage
Correct answer: B
Rationale: The diaphragm regulates light intensity for optimal
contrast.
3. Which technique is used to separate plasma from whole blood?
A. Filtration
B. Centrifugation
C. Precipitation
D. Diffusion
Correct answer: B
Rationale: Centrifugation separates components based on density,
isolating plasma from cells.
4. Which pipette is most accurate for transferring 1 mL of
solution?
A. Volumetric pipette
B. Graduated pipette
C. Pasteur pipette
D. Micropipette
Correct answer: A
Rationale: Volumetric pipettes are calibrated for precise volume
measurements.
,5. Which stain is used to observe bacterial cell walls?
A. Hematoxylin
B. Gram stain
C. Eosin
D. Methylene blue
Correct answer: B
Rationale: Gram staining differentiates bacteria by cell wall
properties.
6. Which lab instrument measures pH of a solution?
A. Thermometer
B. Spectrophotometer
C. pH meter
D. Centrifuge
Correct answer: C
Rationale: A pH meter provides precise measurement of hydrogen
ion concentration.
7. Which solution is used as a negative control in an enzyme
assay?
A. Substrate only
B. Enzyme only
C. Buffer without enzyme or substrate
D. Enzyme and substrate
, Correct answer: C
Rationale: Negative controls ensure that observed activity is due to
the enzyme.
8. Which structure directs the path of light in a microscope?
A. Objective lens
B. Condenser
C. Stage
D. Ocular lens
Correct answer: B
Rationale: The condenser focuses light onto the specimen for
clarity.
9. Which method is used to determine cell size under a
microscope?
A. Micrometer calibration
B. Centrifugation
C. Spectrophotometry
D. Titration
Correct answer: A
Rationale: Calibration with a stage micrometer allows accurate
measurement of cells.
10. Which lab technique is used to separate mixtures based on
molecular size?
