Lecture 3 Flashcards
What is the primary purpose of isolating pure cultures from clinical specimens?
A. To identify the source of infection
B. To test the effectiveness of antibiotics
C. To prepare vaccines
D. To observe the unique characteristics of microorganisms
A
Which method is not a technique used to inoculate media for isolating microorganisms?
A. Streak plate method
B. Spread plate method
C. Pour plate method
D. Filtration method
D
At what temperature are clinical media typically incubated to promote growth of human pathogens?
A. Room temperature (25°C)
B. Body temperature (37°C)
C. Refrigeration temperature (4°C)
D. High temperature (55°C)
B
How do differential media assist in the identification of microorganisms?
A. By suppressing the growth of non-target microbes
B. By highlighting biochemical properties through color changes
C. By promoting faster growth of all microbes
D. By killing pathogenic bacteria
B
What does the appearance of colonies on a solid medium indicate?
A. The presence of viral infections
B. The effectiveness of antibiotic treatment
C. That each colony originates from a single species
D. The chemical composition of the medium
C
Why is aseptic technique important in the isolation of microorganisms?
A. To prevent contamination of the culture by foreign bacteria
B. To enhance the growth rate of microorganisms
C. To differentiate between bacteria and fungi
D. To identify the antibiotics that the microorganisms are resistant to
A
What is the main reason for using different types of culture media to grow microorganisms in a laboratory?
A. To match the nutritional requirements of different microorganisms
B. To allow all microbes to grow at the same rate
C. To speed up the identification process
D. To prevent the formation of spores
A
Which is not a characteristic assessed when identifying microorganisms using colonial morphology?
A. Color
B. Shape
C. Gram stain reaction
D. Size
C
Why is the resolution of a microscope important in microbiology?
A. It determines how quickly a specimen can be examined
B. It affects the ability to distinguish between two close objects
C. It influences the color intensity of stained bacteria
D. It allows for the identification of viruses
B
What is the significance of using a light microscope in studying microorganisms?
A. It can view live bacteria in motion
B. It can magnify specimens up to 1,000,000 times their original size
C. It uses a system of lenses to manipulate the path of light from the specimen to the eye
D. It provides three-dimensional views of the specimen
C
What is the purpose of staining techniques in diagnostic microbiology?
A. To enhance the natural color of microorganisms
B. To differentiate parts of a microorganism
C. To kill microorganisms before examination
D. To prevent microorganisms from spreading
B
Why is the inoculum size important in culturing microorganisms?
A. Larger inoculum sizes prevent contamination
B. It determines the rate of growth and development of colonies
C. Smaller inoculum sizes produce more accurate diagnostic results
D. It affects the color of the medium
D
Which type of medium would be used to grow a microorganism with unknown nutritional requirements?
A. Selective medium
B. Differential medium
C. Enriched medium
D. Minimal medium
C
What is the role of incubation in microbiological culture?
A. To cool the culture to a temperature that slows down bacterial metabolism
B. To provide optimal temperature for enzyme activities necessary for growth
C. To dry out the medium to concentrate nutrients
D. To expose the culture to ultraviolet light to stimulate growth
B
How does the pour plate method differ from the spread plate method?
A. It uses a smaller volume of inoculum
B. Microorganisms are mixed with molten agar
C. It requires additional nutrients
D. It isolates pure cultures from mixed samples
B
