,BIOD 171 Essential Microbiology: Module 2 Exam Questions & Answers
Topic: Microscopy, Staining, and Bacterial Anatomy
1. What is the primary purpose of heat fixation during smear preparation?
o A) To kill the organism and secure it to the slide
o B) To stain the cells
o C) To increase magnification
o D) To hydrate the cells
Answer: A) To kill the organism and secure it to the slide
2. What is the total magnification when using the 100X objective lens with a standard
ocular lens (10X)?
o A) 100X
o B) 1000X
o C) 400X
o D) 2000X
Answer: B) 1000X
3. Resolution in microscopy refers to:
o A) The ability to increase an object’s apparent size
o B) The ability to distinguish two adjacent points as separate
o C) The amount of light a lens can gather
o D) The thickness of the specimen in focus
Answer: B) The ability to distinguish two adjacent points as separate
4. A simple stain:
o A) Uses one dye and reveals shape/arrangement
o B) Differentiates between cell types
o C) Always stains the background
, o D) Requires a decolorizer
Answer: A) Uses one dye and reveals shape/arrangement
5. The Gram stain differentiates bacteria based on differences in their:
o A) Cell wall structure
o B) Capsule composition
o C) Flagella number
o D) Nuclear material
Answer: A) Cell wall structure
6. In a properly executed Gram stain, Gram-positive bacteria appear:
o A) Pink/red
o B) Purple/violet
o C) Colorless
o D) Green
Answer: B) Purple/violet
7. The decolorizer in the Gram stain is typically:
o A) Crystal violet
o B) Iodine
o C) Alcohol or acetone
o D) Safranin
Answer: C) Alcohol or acetone
8. Acid-fast staining is used to identify bacteria with high content of ______ in their cell
walls.
o A) Peptidoglycan
o B) Mycolic acid
o C) Teichoic acid
o D) Lipopolysaccharide
Answer: B) Mycolic acid
Topic: Microscopy, Staining, and Bacterial Anatomy
1. What is the primary purpose of heat fixation during smear preparation?
o A) To kill the organism and secure it to the slide
o B) To stain the cells
o C) To increase magnification
o D) To hydrate the cells
Answer: A) To kill the organism and secure it to the slide
2. What is the total magnification when using the 100X objective lens with a standard
ocular lens (10X)?
o A) 100X
o B) 1000X
o C) 400X
o D) 2000X
Answer: B) 1000X
3. Resolution in microscopy refers to:
o A) The ability to increase an object’s apparent size
o B) The ability to distinguish two adjacent points as separate
o C) The amount of light a lens can gather
o D) The thickness of the specimen in focus
Answer: B) The ability to distinguish two adjacent points as separate
4. A simple stain:
o A) Uses one dye and reveals shape/arrangement
o B) Differentiates between cell types
o C) Always stains the background
, o D) Requires a decolorizer
Answer: A) Uses one dye and reveals shape/arrangement
5. The Gram stain differentiates bacteria based on differences in their:
o A) Cell wall structure
o B) Capsule composition
o C) Flagella number
o D) Nuclear material
Answer: A) Cell wall structure
6. In a properly executed Gram stain, Gram-positive bacteria appear:
o A) Pink/red
o B) Purple/violet
o C) Colorless
o D) Green
Answer: B) Purple/violet
7. The decolorizer in the Gram stain is typically:
o A) Crystal violet
o B) Iodine
o C) Alcohol or acetone
o D) Safranin
Answer: C) Alcohol or acetone
8. Acid-fast staining is used to identify bacteria with high content of ______ in their cell
walls.
o A) Peptidoglycan
o B) Mycolic acid
o C) Teichoic acid
o D) Lipopolysaccharide
Answer: B) Mycolic acid
