Practice Test 2 Flashcards
(15 cards)
- Which of the following best describes hortzontal gene transfer in bacteria?
A. The transfer of genetic material between cells through a process called conjugation.
B. The transfer of genetic material from parent to offspring during call division
C. The mutation of genes within a bacterial cell.
D. All of the above.
A. The transfer of genetic material between cells through a process called conjugation.
- Bacteria undergo asexual reproduction through which of the following processes?
A Mitosis
B. Meiosis
C. Binary fission
D. Binary fusion
C. Binary fission
- What is the purpose of using a selective agar in microbial plating?
A. To encourage the growth of specific types of microorganisms.
B. To allow the growth of a wide range of microorganisms.
C. To inhibit the growth of unwanted microorganisms.
D. To neutralize the pH of the sample.
C. To inhibit the growth of unwanted microorganisms.
- Clostridium botulinum, a bacterium that produces the botulinum toxin, causing botulism can only survive without the presence of oxygen. In terms of its oxygen requirement, what type of bacteria is C. botulinum?
A. Obligate anaerobe
B. Obligate aerobe
C. Microaerophile
D. Facultative anaerobe
A. Obligate anaerobe
- Ernst Ruska’s breakthrough that enabled a magnification millions of times greater was the
A Simple microscope
B. Compound microscope
C. Electron microscope
D. Scanning Electron Microscope
C. Electron microscope
- What is the purpose of staining a biological sample before observing it under a microscope?
A. To make the sample more visible under the microscope.
B. To change the chemical composition of the sample.
C. To kill the cells in the sample.
D. To make the sample more durable for long-term storage.
A. To make the sample more visible under the microscope.
- This technique for plating is frequently employed to enumerate microorganisms in a heterogeneous sample, which is introduced into a molten agar medium before it solidifies.
A. Spread plate technique
B. Pour plate technique
C. Streak plate technique
D. Enumeration method
B. Pour plate technique
- What is the acceptable range of viable counts per plate, as specified by the Bacteriological Analytical Manual (BAM), for calculating colony-forming units for yeast and molds?
A. 10-250 colonies
B. 10-150 colonies
C. 15-150 colonies
D. 25-250 colonies
B. 10-150 colonies
- Penicillin blocks cell wall synthesis. During which phase of the growth cycle would a population
of Streptococcus be most sensitive to penicillin?
A. Lag phase
B. Log phase
C. Stationary phase
D. Death phase
B. Log phase
- How does non-ionizing radiation exert its antimicrobial effect?
A. By inducing DNA damage.
C. By inhibiting protein synthesis
B. By disrupting the cell membrane.
D. By altering membrane potential
A. By inducing DNA damage..
- Salmonella has a generation time of 30 minutes. If four cells are present on a turkey that is left on the counter, how many cells will be present after 3 hours?
A. 12
B. 24
C. 54
D. 256
D. 256
- A bacterial population increases from 103 cells to 108 cells in 6 hours. How many generations have passed? Calculate for the growth rate.
A. 17 generations; 3.23 generations/hr
B. 17 generations; 0.05 generations/min
C. 23 generations; 3.23 generations/hr
D. 23 generations; 0.05 generations/min
B. 17 generations; 0.05 generations/min
- A bacterial population increases from 10 cells to 10 cells in 6 hours. What is the doubling time?
A. 1.30 hours
B. 0.95 hours
C. 0.35 hours
D. 0.53 hours
C. 0.35 hours
- What is the color of the cells containing endospores after staining?
A. Pink
B. Green
C. Blue
D. Violet
B. Green
- The following results to a pink/red stain, except for
A. Gram negative bacteria
B. Acid-fast bacteria
C. Vegetative cells
D. Non-acid fast bacteria
D. Non-acid fast bacteria
