Portage Learning| BIOL 271 Microbiology Lab 3 Exams All Versions; Questions With Verified Answers

Portage Learning| BIOL 271 Microbiology Lab 3
Exams All Versions; Questions With Verified Answers


Institution: Portage Learning
Course Code: BIOL 271
Course Title: Microbiology W/ Lab
Exam: Lab 3 Exams

Topic: Gram Staining
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!!

,Gram Staining

Question 1.
What Is A Type Of Differential Staining?
A. Gram Staining
B. Simple Staining
C. Structural Staining
D. Negative Staining
ANS. A.
Explanation: Gram Staining Is A Differential Staining Technique Used To Differentiate
Bacteria Based On Differences In Their Cell Wall Structure.


Question 2.
What Materials Are Needed For Gram Staining?
A. Crystal Violet, Gram's Iodine, 95% Ethanol, Safranin
B. Crystal Violet, Gram's Iodine, Methylene Blue, Safranin
C. Crystal Violet, 95% Ethanol, Methylene Blue, Safranin
D. Gram's Iodine, 95% Ethanol, Methylene Blue, Safranin
ANS. A.
Explanation: The Gram Staining Procedure Uses Crystal Violet, Gram's Iodine, 95%
Ethanol, And Safranin As Its Main Reagents.


Question 3.
Identify The Gram Status Of The Bacteria Pictured Below.

,A. Gram Positive (+) Bacteria
B. Gram Negative (-) Bacteria
C. Acid-Fast Bacteria
D. Pleomorphic Bacteria
ANS. A.
Explanation: Gram-Positive Bacteria Retain The Crystal Violet-Iodine Complex During
Gram Staining And Appear Purple.


Question 4.
Identify The Gram Status Of The Bacteria Pictured Below.

, A. Gram Positive (+) Bacteria
B. Gram Negative (-) Bacteria
C. Acid-Fast Bacteria
D. Pleomorphic Bacteria
ANS. B.
Explanation: Gram-Negative Bacteria Lose The Crystal Violet Stain During
Decolorization And Take Up The Safranin Counterstain, Appearing Pink Or Red.


Question 5.
Why Is It Important To Use Cells Less Than 24 Hours Hours Of Age With The Gram
Stain Procedure?
A. Because It Can Result In A False Gram-Negative Result/ Staining.
B. Because It Can Result In A False Gram-Positive Result/ Staining.
C. Because Older Cells Cannot Absorb Crystal Violet.
D. Because Older Cells Cannot Absorb Safranin.
ANS. A.
Explanation: Older Bacterial Cells Can Have Altered Cell Wall Properties That May
Cause An Incorrect Gram-Negative Staining Result.


Question 6.
Identify The Gram Status (Positive Or Negative) And Shape Of The Bacteria Pictured
Below.