KING ABDULAZIZ UNIVERSITY
FACULTY OF SCIENCE
Department of Biological Science
Course Title & Code: GENERAL MICROBIOLOGY (BIO 231)
Mid Term Exam
Student's Name: ……………………………………………………………
UID: …………………… Date ………………….
(MODEL ANSWER)
1.Multiple Choice Questions
1) Organisms that require high salt concentrations for growth are called:
A) halophiles.
B) extreme halophiles.
C) facultative halophiles.
D) microhalophiles.
2) Which of the following pairs is mismatched?
A) psychrotroph — growth at 0°C
B) thermophile — growth at 37°C
C) mesophile — growth at 25°C
D) psychrophile — growth at 15°C
E) hyperthermophiles — growth at 85°C
3) Most fungi grow best at pH
A) 1.
B) 5.
C) 7.
D) 9.
E) 14.
4) Some microorganisms use gaseous nitrogen directly from the atmosphere in a process called:
A) chemosynthesis.
B) photosynthesis.
C) nitrogen fixation.
D) nitrogen synthesis.
5) Which of the following types of media would not be used to culture aerobes?
A) selective media
B) reducing media
D) differential media
C) enrichment media
E) complex media
6) The addition of which of the following to a culture medium will neutralize acids?
A) buffers
B) sugars
C) pH
D) heat
E) carbon
7) Which of the following is an advantage of the standard plate count?
A) can readily count cells that form aggregates
B) determines the number of viable cells
C) can be performed on very dilute samples, such as lake water
D) provides immediate results
E) can be used to count heat-sensitive bacteria
Figure 1.2
8) Figure 1.2 shows a typical bacterial growth curve with the x-axis indicating the log of the number of bacteria and the y-axis indicating time in culture. In the figure, which section (or sections) shows a growth phase where the number of cells dying equals the number of cells dividing?
A) a
B) b
C) c
D) d
9) Which of the following is NOT a direct method to measure microbial growth?
A) direct microscopic count
B) standard plate count
C) filtration
D) metabolic activity
E) most probable number (MPN)
10) Which of the following is an organic growth factor?
A) glucose
B) vitamin B1
C) peptone
D) NH4H2PO4
E) H2O
11) Which of the following does not belong with the others?
A) Enterobacteriales
B) Lactobacillales
C) Legionellales
D) Pasteurellales
D) Vibrionales
12) Which of the following is an intracellular parasite?
A) Rickettsia
B) Mycobacterium
C) Bacillus
D) Staphylococcus
E) Streptococcus
13) Cyanobacteria differ from purple and green phototrophic bacteria because cyanobacteria
A) produce oxygen during photosynthesis.
B) do not require light.
C) use H2S as an electron donor.
D) have a membrane-enclosed nucleus.
E) all of the above
14) Which of the following is NOT a characteristic of Neisseria?
A) requires X and V factors
B) cocci
C) gram-negative
D) oxidase-positive
E) Some species are human pathogens.
15) Which of the following do you expect to be MOST resistant to high temperatures?
A) Bacillus subtilis
B) Eschericia coli
C) Neisseria gonorrhoeae
D) Staphylococcus aureus
E) Streptococcocus pyogenes
16) Which of the following is NOT an enteric?
A) Salmonella
B) Shigella
C) Escherichia
D) Enterobacter
E) Campylobacter
17) Which of the following form conidiospores?
A) endospore-forming gram-positive rods and cocci
B) actinomycetes and related organisms
C) rickettsias
D) anaerobic gram-negative cocci
E) spiral and curved bacteria
18) Requirements for X and V factors are used to identify
A) Staphylococcus.
B) Escherichia.
C) Neisseria.
D) Haemophilus.
E) Pseudomonas.
19) Which of the following is the best reason to classify Streptococcus in the Lactobacillales?
A) Gram reaction
B) morphology
C) fermentation of lactose
D) rRNA sequences
E) found in dairy products
20) Caulobacter are different from most bacteria in that they
A) are gram-negative.
B) are gram-positive.
C) have stalks.
D) lack cell walls.
E) are motile.
Π-True/False Questions
1) An isolated colony on a streak plate contains millions or billions of identical cells (TRUE)
2) Most pathogenic bacteria are thermophiles (FALSE) Mesophiles
3) Laboratory cultivation of obligate anaerobes requires reducing media or special growth chambers filled with inert gases (TRUE)
4) Turbidity is an indirect measurement of bacterial growth that can be measured using a spectrophotometer (TRUE)
5) Bacterial predators such as Bdellovibrio are members of the betaproteobacteria
(FALSE)Deltaproteobacteria
6) Two distinguishing factors of the epsilonproteobacteria that they are motile and microaerophilic (TRUE)
7) All gram-negative bacteria are classified as proteobacteria (FALSE) as Proteobacteria
and Non proteobacteria
8) Photosynthetic organisms always produce oxygen gas as a metabolic byproduct (FALSE)
Co2
9) Currently, no members of Archaea have been linked to human disease (TRUE)
10) Filtration methods are used to count bacteria present in very low concentrations, such as in lakes and streams (TRUE)
Good Luck
KING ABDULAZIZ UNIVERSITY
FACULTY OF SCIENCE
Department of Biological Science
Course Title & Code: GENERAL MICROBIOLOGY (BIO 231)
Mid Term Exam
Student's Name: ……………………………………………………………
UID: …………………… Date ………………….
1.Multiple Choice Questions
1) Organisms that require high salt concentrations for growth are called:
A) halophiles.
B) extreme halophiles.
C) facultative halophiles.
D) microhalophiles.
2) Which of the following pairs is mismatched?
A) psychrotroph — growth at 0°C
B) thermophile — growth at 37°C
C) mesophile — growth at 25°C
D) psychrophile — growth at 15°C
E) hyperthermophiles — growth at 85°C
3) Most fungi grow best at pH
A) 1.
B) 5.
C) 7.
D) 9.
E) 14.
4) Some microorganisms use gaseous nitrogen directly from the atmosphere in a process called:
A) chemosynthesis.
B) photosynthesis.
C) nitrogen fixation.
D) nitrogen synthesis.
5) Which of the following types of media would not be used to culture aerobes?
A) selective media
B) reducing media
D) differential media
C) enrichment media
E) complex media
6) The addition of which of the following to a culture medium will neutralize acids?
A) buffers
B) sugars
C) pH
D) heat
E) carbon
7) Which of the following is an advantage of the standard plate count?
A) can readily count cells that form aggregates
B) determines the number of viable cells
C) can be performed on very dilute samples, such as lake water
D) provides immediate results
E) can be used to count heat-sensitive bacteria
Figure 1.2
8) Figure 1.2 shows a typical bacterial growth curve with the x-axis indicating the log of the number of bacteria and the y-axis indicating time in culture. In the figure, which section (or sections) shows a growth phase where the number of cells dying equals the number of cells dividing?
A) a
B) b
C) c
D) d
9) Which of the following is NOT a direct method to measure microbial growth?
A) direct microscopic count
B) standard plate count
C) filtration
D) metabolic activity
E) most probable number (MPN)
10) Which of the following is an organic growth factor?
A) glucose
B) vitamin B1
C) peptone
D) NH4H2PO4
E) H2O
11) Which of the following does not belong with the others?
A) Enterobacteriales
B) Lactobacillales
C) Legionellales
D) Pasteurellales
D) Vibrionales
12) Which of the following is an intracellular parasite?
A) Rickettsia
B) Mycobacterium
C) Bacillus
D) Staphylococcus
E) Streptococcus
13) Cyanobacteria differ from purple and green phototrophic bacteria because cyanobacteria
A) produce oxygen during photosynthesis.
B) do not require light.
C) use H2S as an electron donor.
D) have a membrane-enclosed nucleus.
E) all of the above
14) Which of the following is NOT a characteristic of Neisseria?
A) requires X and V factors
B) cocci
C) gram-negative
D) oxidase-positive
E) Some species are human pathogens.
15) Which of the following do you expect to be MOST resistant to high temperatures?
A) Bacillus subtilis
B) Eschericia coli
C) Neisseria gonorrhoeae
D) Staphylococcus aureus
E) Streptococcocus pyogenes
16) Which of the following is NOT an enteric?
A) Salmonella
B) Shigella
C) Escherichia
D) Enterobacter
E) Campylobacter
17) Which of the following form conidiospores?
A) endospore-forming gram-positive rods and cocci
B) actinomycetes and related organisms
C) rickettsias
D) anaerobic gram-negative cocci
E) spiral and curved bacteria
18) Requirements for X and V factors are used to identify
A) Staphylococcus.
B) Escherichia.
C) Neisseria.
D) Haemophilus.
E) Pseudomonas.
19) Which of the following is the best reason to classify Streptococcus in the Lactobacillales?
A) Gram reaction
B) morphology
C) fermentation of lactose
D) rRNA sequences
E) found in dairy products
20) Caulobacter are different from most bacteria in that they
A) are gram-negative.
B) are gram-positive.
C) have stalks.
D) lack cell walls.
E) are motile.
Π-True/False Questions
1) An isolated colony on a streak plate contains millions or billions of identical cells ( )
2) Most pathogenic bacteria are thermophiles ( )
3) Laboratory cultivation of obligate anaerobes requires reducing media or special growth
chambers filled with inert gases ( )
4) Turbidity is an indirect measurement of bacterial growth that can be measured using a
spectrophotometer ( )
5) Bacterial predators such as Bdellovibrio are members of the betaproteobacteria ( )
6) Two distinguishing factors of the epsilonproteobacteria that they are motile and
microaerophilic ( )
7) All gram-negative bacteria are classified as proteobacteria ( )
8) Photosynthetic organisms always produce oxygen gas as a metabolic byproduct ( )
9) Currently, no members of Archaea have been linked to human disease ( )
10) Filtration methods are used to count bacteria present in very low concentrations, such as in
lakes and streams ( )
Good Luck