EXCERCISE 4.1-4.2 LAB MICROBIO Flashcards

1.What is one of the most important steps in identifying a new bacteria or one isolated from a patient’s specimen?
A) Measuring bacterial growth rate
B) Noting colony morphology
C) Performing a DNA test
D) Observing bacterial motility

1.What can cause variations in colony morphology?
A) The type of microscope used
B) Nutrients present in various media or incubation conditions
C) The color of the agar
D) The size of the Petri dish

1.Which bacteria are not cultured in the lab due to being pathogens or having unavailable growth conditions?
A) Escherichia coli
B) Mycobacterium, Mycoplasma, Chlamydia, and Rickettsia
C) Bacillus and Clostridium
D) Streptococcus and Staphylococcus

1.Why are Mycoplasma species pleomorphic?
A) They have a thick cell wall
B) They have no cell wall
C) They are rod-shaped
D) They are spiral-shaped

1.What is the purpose of the acid-fast stain?
A) To identify Gram-positive bacteria
B) To identify Mycobacterium and related bacteria
C) To stain bacterial capsules
D) To visualize bacterial flagella

1.What is used to stain the waxy cell wall of Mycobacterium in the acid-fast stain?
A) Methylene blue
B) Carbolfuchsin
C) Crystal violet
D) Safranin

1.What is the function of bacterial capsules in some strains?
A) To aid in bacterial motility
B) To protect the microbe from host defense mechanisms
C) To help in nutrient absorption
D) To assist in bacterial reproduction

1.What staining technique is used to visualize bacterial flagella?
A) Gram stain
B) Acid-fast stain
C) Special staining techniques with a stain and mordant
D) Negative stain

1.Which genera of bacteria are most characteristic of endospore formation?
A) Escherichia and Salmonella
B) Mycobacterium and Mycoplasma
C) Bacillus and Clostridium
D) Streptococcus and Staphylococcus

1.What stain is used to visualize endospores in Bacillus cultures?
A) Crystal violet
B) Safranin
C) Malachite green

1.What is the purpose of performing Gram stains on organisms after observing colony morphology?
A) To measure bacterial growth rate
B) Identify some cell wall components and cellular morphology
C) To identify bacterial motility
D) To observe bacterial spores

1.What special stains are available for identifying bacterial surface structures or internal components?
A) Gram stain and acid-fast stain
B) Capsule stain and flagella stain
C) Simple stain and negative stain
D) Methylene blue and crystal violet

1.What unique component in the cell wall of Mycobacterium prevents it from staining with simple and Gram stains?
A) Peptidoglycan
B) Lipopolysaccharides
C) Mycolic acids
D) Teichoic acids

1.What is the counterstain used in the acid-fast stain to visualize non-acid-fast bacteria?
A) Crystal violet
B) Methylene blue
C) Safranin
D) Carbolfuchsin

1.Why is the acid-fast stain important for diagnosing mycobacterial diseases?
A) Mycobacterium grows quickly in culture
B) Mycobacterium grows very slowly in culture
C) Mycobacterium does not grow in culture
D) Mycobacterium is easily identified by Gram stain

1.What is the purpose of using a mordant in flagella staining?
A) To fix the stain to the cell wall
B) To increase the diameter of the flagella for viewing
C) To decolorize the flagella
D) To counterstain the flagella

1.What is the appearance of endospores after staining with malachite green and safranin?
A) Red in red bacterial cells
B) Green in green bacterial cells
C) Green in red bacterial cells
D) Red in green bacterial cells
D) Carbolfuchsin