KING ABDULAZIZ UNIVERSITYFACULTY OF SCIENCE

Department of Biological Science Course Title & Code: GENERAL MICROBIOLOGY (BIO 231)

Mid Term ExamStudent'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°CB) thermophile — growth at 37°CC) mesophile — growth at 25°CD) psychrophile — growth at 15°CE) hyperthermophiles — growth at 85°C

3) Most fungi grow best at pHA) 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 mediaB) reducing media D) differential mediaC) enrichment media E) complex media

6) The addition of which of the following to a culture medium will neutralize acids?A) buffersB) sugarsC) pHD) heatE) 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 cellsC) can be performed on very dilute samples, such as lake waterD) provides immediate resultsE) 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) aB) bC) cD) d

9) Which of the following is NOT a direct method to measure microbial growth?A) direct microscopic countB) standard plate countC) filtrationD) metabolic activityE) most probable number (MPN)

10) Which of the following is an organic growth factor?

A) glucoseB) vitamin B1 C) peptoneD) NH4H2PO4E) H2O

11) Which of the following does not belong with the others?A) EnterobacterialesB) Lactobacillales C) LegionellalesD) PasteurellalesD) Vibrionales

12) Which of the following is an intracellular parasite?A) Rickettsia B) Mycobacterium C) BacillusD) StaphylococcusE) Streptococcus

13) Cyanobacteria differ from purple and green phototrophic bacteria because cyanobacteriaA) 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 factorsB) cocciC) gram-negativeD) oxidase-positiveE) Some species are human pathogens.

15) Which of the following do you expect to be MOST resistant to high temperatures?A) Bacillus subtilisB) Eschericia coliC) Neisseria gonorrhoeaeD) Staphylococcus aureusE) Streptococcocus pyogenes

16) Which of the following is NOT an enteric?A) SalmonellaB) ShigellaC) EscherichiaD) Enterobacter

E) Campylobacter

17) Which of the following form conidiospores?A) endospore-forming gram-positive rods and cocciB) actinomycetes and related organismsC) rickettsiasD) anaerobic gram-negative cocciE) spiral and curved bacteria

18) Requirements for X and V factors are used to identifyA) 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 reactionB) morphologyC) fermentation of lactoseD) rRNA sequencesE) found in dairy products

20) Caulobacter are different from most bacteria in that theyA) 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 UNIVERSITYFACULTY OF SCIENCE

Department of Biological Science Course Title & Code: GENERAL MICROBIOLOGY (BIO 231)

Mid Term ExamStudent'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°CB) thermophile — growth at 37°CC) mesophile — growth at 25°CD) psychrophile — growth at 15°CE) hyperthermophiles — growth at 85°C

3) Most fungi grow best at pHA) 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 mediaB) reducing media D) differential mediaC) enrichment media E) complex media

6) The addition of which of the following to a culture medium will neutralize acids?A) buffersB) sugarsC) pHD) heatE) 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 cellsC) can be performed on very dilute samples, such as lake waterD) provides immediate resultsE) 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) aB) bC) cD) d

9) Which of the following is NOT a direct method to measure microbial growth?A) direct microscopic countB) standard plate countC) filtrationD) metabolic activityE) most probable number (MPN)

10) Which of the following is an organic growth factor?A) glucoseB) vitamin B1 C) peptoneD) NH4H2PO4E) H2O

11) Which of the following does not belong with the others?A) EnterobacterialesB) Lactobacillales C) LegionellalesD) PasteurellalesD) Vibrionales

12) Which of the following is an intracellular parasite?A) Rickettsia B) Mycobacterium C) BacillusD) StaphylococcusE) Streptococcus

13) Cyanobacteria differ from purple and green phototrophic bacteria because cyanobacteriaA) 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 factorsB) cocciC) gram-negativeD) oxidase-positiveE) Some species are human pathogens.

15) Which of the following do you expect to be MOST resistant to high temperatures?A) Bacillus subtilisB) Eschericia coliC) Neisseria gonorrhoeaeD) Staphylococcus aureusE) Streptococcocus pyogenes

16) Which of the following is NOT an enteric?A) SalmonellaB) ShigellaC) EscherichiaD) EnterobacterE) Campylobacter

17) Which of the following form conidiospores?A) endospore-forming gram-positive rods and cocciB) actinomycetes and related organismsC) rickettsias

D) anaerobic gram-negative cocciE) spiral and curved bacteria

18) Requirements for X and V factors are used to identifyA) 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 reactionB) morphologyC) fermentation of lactoseD) rRNA sequencesE) found in dairy products

20) Caulobacter are different from most bacteria in that theyA) 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