Portage Learning| BIOL 271 Microbiology w/ Lab Module 3
Exam All Versions; Latest Questions With Verified Answers
Institution: Portage Learning
Course Code: BIOL 271
Course Title: Microbiology w/ Lab
Exam: Module 3 Exam
Topic: Microscopy And Microbial Staining Techniques
Edition: Updated Version
Student Name: _______________________________
Student Id: _________________________________
Instructor: _________________________________
Instructions:
• Answer All Questions.
• Choose The Correct Answer
QUESTIONS TYPE:
➢ Multiple Choice:
➢ True Or False:
➢ Explain/Describe/ Identification
➢ Fill In The Blank
➢ Short Answer
All The Best!!
,Microscopy And Microbial Staining Techniques
1. A Micrometer Is Defined As:
A. 10^-3
B. 10^-6
C. 10^-9
D. 10^-12
ANS. B.
Explanation: A Micrometer (µm) Is Equal To 10^-6 Meters.
2. Assuming A Fixed Ocular, Identify The Part Of The Microscope You Would Adjust
To Enhance The Magnification Of A Sample.
A. Objective
B. Eyepiece
C. Condenser Lens
D. Iris Diaphragm
ANS. A.
Explanation: With A Fixed Ocular, Changing The Objective Provides A Different Level
Of Magnification.
3. What Is The Total Magnification (Relative To Your Eye) Of A Sample Imaged With A
60x Objective And A 10x Eyepiece?
A. 60x
B. 100x
C. 600x
D. 6000x
ANS. C.
Explanation: Total Magnification = Objective × Eyepiece = 60 × 10 = 600x.
,4. Resolution And Contrast Are Two Critical Factors That Influence Your Ability To See
An Object. Explain Each.
ANS.
Resolution Is The Distance Between Objects At Which They Appear Separate. Poor
Resolution Can Show Two Or More Objects As Just One.
Contrast Is The Difference In Light Absorption Between Two Objects. Poor Contrast Can
Make The Visualization Of Multiple Object Difficult.
Explanation: Resolution Determines The Ability To Distinguish Separate Objects, While
Contrast Refers To Differences In Light Absorption That Make Objects Distinguishable.
5. True Or False: A Cell That Is Adherent, Flat, And Unstained Is Easily Identified Using
Bright Field Microscopy.
A. True
B. False
ANS. B.
Explanation: Adherent, Flat Cells Are Almost Invisible Due To The Limits On Both
Resolution And Contrast.
6. Which Of The Following Could Be Seen Clearly By The Unaided Eye. Select All That
Apply.
A. Virus With A Diameter Of 0.2 Micrometers
B. Bacteria With A Diameter Of 24 Micrometers
C. Skin Cell With A Diameter Of 1500 Micrometers
D. Protozoa With A Diameter Of 150 Micrometers
ANS. C And D.
Explanation: The Unaided Eye Can See Objects >150 Micrometers.
7. Label The Following Microscope Components.
,Choices:
A. Stage
B. Fine Adjustment Knob
C. Iris Diaphragm
D. Neck
E. Condenser Lens
F. Eyepiece
G. Objective
H. Base
I. Coaxial Controls
ANS.
1. F — Eyepiece
2. D — Neck
3. B — Fine Adjustment Knob
4. G — Objective
5. A — Stage
6. H — Base
,Explanation: The Numbered Structures Correspond To The Microscope Components
Identified By The Provided Answers.
8. This Type Of Microscope Is Best Suited For Visualizing Gfp, Rfp, And Yfp Proteins.
ANS. Fluorescence
Explanation: Fluorescence Microscopy Is Used To Visualize Fluorescent Proteins Such
As GFP, RFP, AND YFP.
9. This Type Of Microscope Uses A Specialized Condenser And Objective To Amplify
The Slight Differences Between Cells And Background.
ANS. Phase-Contrast
Explanation: Phase-Contrast Microscopy Enhances Slight Differences In Refractive
Index And Contrast Between Cells And Their Background.
10. This Type Of Microscope Enhances Contrast Between Specimen And Background
But Does Not Permit The Visualization Of Intracellular Structures.
ANS. Dark Field
Explanation: Dark-Field Microscopy Increases Contrast By Making The Specimen
Appear Bright Against A Dark Background, But It Does Not Show Intracellular
Structures.
11. This Type Of Microscope Is Capable Of Capturing Images In Multiple Focal Planes,
Rendering A Specimen In 3-D.
ANS. Confocal
Explanation: Confocal Microscopy Captures Optical Sections At Multiple Focal Planes
That Can Be Used To Create Three-Dimensional Images.
12. Identify What Type Of Electron Microscope Was Used To Capture The Following
Image And Explain Your Choice.
, ANS. Scanning Electron Microscope. Only The Shells Are Visible
Explanation: Scanning Electron Microscopy Provides Detailed Views Of Specimen
Surfaces, Which Is Consistent With Only The Shells Being Visible.
13. Gram-Positive Cells Appear [...] In Color Due To A [...] Peptidoglycan Layer In The
Cell Wall.
A. Purple; Thick
B. Pink; Thin
C. Purple; Thin
D. Pink; Thick
ANS. A.
Explanation: Gram-Positive Cells Retain The Crystal Violet Stain Because Of Their
Thick Peptidoglycan Layer.
14. Gram-Negative Cells Appear [...] In Color Due To A [...] Peptidoglycan Layer In The
Cell Wall.
A. Purple; Thick
B. Pink; Thin
Exam All Versions; Latest Questions With Verified Answers
Institution: Portage Learning
Course Code: BIOL 271
Course Title: Microbiology w/ Lab
Exam: Module 3 Exam
Topic: Microscopy And Microbial Staining Techniques
Edition: Updated Version
Student Name: _______________________________
Student Id: _________________________________
Instructor: _________________________________
Instructions:
• Answer All Questions.
• Choose The Correct Answer
QUESTIONS TYPE:
➢ Multiple Choice:
➢ True Or False:
➢ Explain/Describe/ Identification
➢ Fill In The Blank
➢ Short Answer
All The Best!!
,Microscopy And Microbial Staining Techniques
1. A Micrometer Is Defined As:
A. 10^-3
B. 10^-6
C. 10^-9
D. 10^-12
ANS. B.
Explanation: A Micrometer (µm) Is Equal To 10^-6 Meters.
2. Assuming A Fixed Ocular, Identify The Part Of The Microscope You Would Adjust
To Enhance The Magnification Of A Sample.
A. Objective
B. Eyepiece
C. Condenser Lens
D. Iris Diaphragm
ANS. A.
Explanation: With A Fixed Ocular, Changing The Objective Provides A Different Level
Of Magnification.
3. What Is The Total Magnification (Relative To Your Eye) Of A Sample Imaged With A
60x Objective And A 10x Eyepiece?
A. 60x
B. 100x
C. 600x
D. 6000x
ANS. C.
Explanation: Total Magnification = Objective × Eyepiece = 60 × 10 = 600x.
,4. Resolution And Contrast Are Two Critical Factors That Influence Your Ability To See
An Object. Explain Each.
ANS.
Resolution Is The Distance Between Objects At Which They Appear Separate. Poor
Resolution Can Show Two Or More Objects As Just One.
Contrast Is The Difference In Light Absorption Between Two Objects. Poor Contrast Can
Make The Visualization Of Multiple Object Difficult.
Explanation: Resolution Determines The Ability To Distinguish Separate Objects, While
Contrast Refers To Differences In Light Absorption That Make Objects Distinguishable.
5. True Or False: A Cell That Is Adherent, Flat, And Unstained Is Easily Identified Using
Bright Field Microscopy.
A. True
B. False
ANS. B.
Explanation: Adherent, Flat Cells Are Almost Invisible Due To The Limits On Both
Resolution And Contrast.
6. Which Of The Following Could Be Seen Clearly By The Unaided Eye. Select All That
Apply.
A. Virus With A Diameter Of 0.2 Micrometers
B. Bacteria With A Diameter Of 24 Micrometers
C. Skin Cell With A Diameter Of 1500 Micrometers
D. Protozoa With A Diameter Of 150 Micrometers
ANS. C And D.
Explanation: The Unaided Eye Can See Objects >150 Micrometers.
7. Label The Following Microscope Components.
,Choices:
A. Stage
B. Fine Adjustment Knob
C. Iris Diaphragm
D. Neck
E. Condenser Lens
F. Eyepiece
G. Objective
H. Base
I. Coaxial Controls
ANS.
1. F — Eyepiece
2. D — Neck
3. B — Fine Adjustment Knob
4. G — Objective
5. A — Stage
6. H — Base
,Explanation: The Numbered Structures Correspond To The Microscope Components
Identified By The Provided Answers.
8. This Type Of Microscope Is Best Suited For Visualizing Gfp, Rfp, And Yfp Proteins.
ANS. Fluorescence
Explanation: Fluorescence Microscopy Is Used To Visualize Fluorescent Proteins Such
As GFP, RFP, AND YFP.
9. This Type Of Microscope Uses A Specialized Condenser And Objective To Amplify
The Slight Differences Between Cells And Background.
ANS. Phase-Contrast
Explanation: Phase-Contrast Microscopy Enhances Slight Differences In Refractive
Index And Contrast Between Cells And Their Background.
10. This Type Of Microscope Enhances Contrast Between Specimen And Background
But Does Not Permit The Visualization Of Intracellular Structures.
ANS. Dark Field
Explanation: Dark-Field Microscopy Increases Contrast By Making The Specimen
Appear Bright Against A Dark Background, But It Does Not Show Intracellular
Structures.
11. This Type Of Microscope Is Capable Of Capturing Images In Multiple Focal Planes,
Rendering A Specimen In 3-D.
ANS. Confocal
Explanation: Confocal Microscopy Captures Optical Sections At Multiple Focal Planes
That Can Be Used To Create Three-Dimensional Images.
12. Identify What Type Of Electron Microscope Was Used To Capture The Following
Image And Explain Your Choice.
, ANS. Scanning Electron Microscope. Only The Shells Are Visible
Explanation: Scanning Electron Microscopy Provides Detailed Views Of Specimen
Surfaces, Which Is Consistent With Only The Shells Being Visible.
13. Gram-Positive Cells Appear [...] In Color Due To A [...] Peptidoglycan Layer In The
Cell Wall.
A. Purple; Thick
B. Pink; Thin
C. Purple; Thin
D. Pink; Thick
ANS. A.
Explanation: Gram-Positive Cells Retain The Crystal Violet Stain Because Of Their
Thick Peptidoglycan Layer.
14. Gram-Negative Cells Appear [...] In Color Due To A [...] Peptidoglycan Layer In The
Cell Wall.
A. Purple; Thick
B. Pink; Thin
