MCQs Microbiology :: Growth of Bacteria

1.
Which of the following is not the characteristic of a growth curve?

A. Shows development of microbial population under relatively stable environmental conditions
B. Plotted with logarithmic numbers
C. Graphs numbers of microbes versus time
D. Each growth curve consists of four distinct phases
Answer & Explanation
Answer: Option D

2.
Generation time of Escherichia coli is

A. 20 minutes
B. 20 hours
C. 20 days
D. 200 hours
Answer & Explanation
Answer: Option A

Explanation:

3.
The organism which obtain their energy from chemicals are designated as

A. prototrophs B. chemotrophs
C. organotrophs D. autotrophs
Answer & Explanation
Answer: Option B

4.
Nutrient content and biological structures are considered as

A. implicit factor for microbial growth
B. intrinsic factor for microbial growth
C. processing factor
D. none of the above
Answer & Explanation
Answer: Option B

5.
The organism which grows best above 45°C are called

A. psychrophilic
B. mesosphilic
C. thermophilic
D. any of these
Answer & Explanation
Answer: Option C

6.
Implicit factors

A. depend on developing microflora
B. can be synergistic
C. both (a) and (b)
D. none of the above
Answer & Explanation
Answer: Option C

7.
Lag phase is also known as

A. period of initial adjustment
B. transitional period
C. generation time
D. none of these
Answer & Explanation
Answer: Option A

8.
Which of the following is used to grow bacterial cultures continuously?

A. Chemostat
B. Coulter Counter
C. Hemostat
D. Petroff-Hausser chamber
Answer & Explanation
Answer: Option A

9.
A microbe, which grows at temperatures above 95° C is most likely to be

A. an archaean
B. a fungus
C. a protozoan
D. none of these
Answer & Explanation
Answer: Option A

10.
Some organisms can use reduced inorganic compounds as electron donors and are termed as

A. lithotrophs B. phototrophs
C. chemotrophs D. photo-organotrophs
Answer & Explanation
Answer: Option A

11.
The total biomass of an organism will be determined by the nutrient present in the lowest concentration relative to the organism's requirements is a statement of

A. Liebig's law of the minimum
B. Shelford's law of tolerance
C. quorum sensing
D. Heisenberg's principle of uncertainty
Answer & Explanation
Answer: Option A

12.
The growth is normally expressed as __________ in turbidimetric measurement

A. cells per ml
B. cfu/ml
C. optical density
D. mg N2 /ml
Answer & Explanation
Answer: Option C

12.
The growth is normally expressed as __________ in turbidimetric measurement

A. cells per ml
B. cfu/ml
C. optical density
D. mg N2 /ml
Answer & Explanation
Answer: Option C

14.
An organism that expends energy to grow in a habitat with a low water activity in order to maintain internal solute concentrations to retain water is

A. osmotolerant
B. acidophile
C. aerotolerant anaerobe
D. alkalophile
Answer & Explanation
Answer: Option A

15.
The straightforward method of binary fission explains how bacteria

A. grow in nutrient agar
B. evolve
C. move
D. reproduce
Answer & Explanation
Answer: Option D

16.
The equation used to obtain bacterial population by binary fission is

A. N = No2n
B. log N/No = (0.3010) n
C. log(N/No) = nlog 2
D. All of these
Answer & Explanation
Answer: Option D

17.
Bacteria and fungi multiply best

A. below 16°C
B. between 16-38°C
C. above 38°C
D. none of these
Answer & Explanation
Answer: Option B

18.
An organism has an optimal growth rate when the hydrogen ion concentration is very high. This organism is

A. osmotolerant
B. acidophile
C. neutrophile
D. aerotolerant anaerobe
Answer & Explanation
Answer: Option B

19.
Which of the following procedures uses a photocell to measure absorbance of a culture to regulate the flow of culture media?

A. Coulter Counter
B. Hemostat
C. Petroff-Hausser chamber
D. Trubidostat
Answer & Explanation
Answer: Option D

20.
Organisms, using organic compounds as electron donors are called

A. lithotrophs B. phototrophs
C. chemotrophs D. organotrophs
Answer & Explanation
Answer: Option D

21.
The reproduction by budding occur in

A. Rhodopseudomonas acidophila
B. Hyphomicrobium vulgare
C. Bacillus subtilis
D. Both (a) and (b)
Answer & Explanation
Answer: Option D

22.
Starvation proteins are produced by a culture during which of the following segments of the growth curve?

A. Lag phase
B. Exponential phase
C. Stationary phase
D. Death phase
Answer & Explanation
Answer: Option C

23.
The cell reproduction in bacteria may occur by

A. binary fission
B. budding
C. fragmentation
D. all of these
Answer & Explanation
Answer: Option D

24.
During exponential growth, the growth rate is

A. number of generations per unit time
B. reciprocal of generation time
C. both (a) and (b)
D. none of these
Answer & Explanation
Answer: Option B

25.
A spore differs from an actively replicating bacterium in that the spore

A. is produced during a process involving asymmetric division
B. is able to withstand more extreme conditions than the replicating cell
C. is metabolically inactive
D. all of the above
Answer & Explanation
Answer: Option D

26.
Which of the following has more tolerance for acidic pH (lower pH)?

A. Yeast and moulds
B. Bacteria
C. E. coli
D. None of these
Answer & Explanation
Answer: Option A

27.
The ability of Vibrio fischeri to produce bioluminescence chemicals only when a certain population density has been reached is an example of

A. Liebig's law of the minimum
B. Shelford's law of tolerance
C. quorum sensing
D. Heisenberg's principle of uncertainty
Answer & Explanation
Answer: Option C

28.
Antimicrobial constituents for the microbial growth in foods are

A. intrinsic factor
B. extrinsic factor
C. both (a) and (b)
D. none of these
Answer & Explanation
Answer: Option A

29.
The average size of cells during the exponential phase of growth is

A. greater than the lag phase
B. lesser than the lag phase
C. equal to the lag phase
D. none of these
Answer & Explanation
Answer: Option B

30.
A culture broth tube was very turbid at the surface but clear throughout the rest of the tube indicating that the

A. organism are aerobes
B. organism should be grown in an anaerobic chamber
C. organism cannot produce superoxide dismutase and/or catalase
D. organism cannot tolerate oxygen
Answer & Explanation
Answer: Option A