MI203 MCQs

What was the volume of the innoculum fluid supplied with the BBL Crystal kit? a. 4.5 ml b. 2.5 ml c. 2.2 ml d. 1 ml

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Why would a scientist perform a bacterial spread plate experiment? a. for plate counts b. for screening c. for selection d. all of the above

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What volume of bacterial inoculum was added in the MIC experiment? a. 0.1 ml b. 0.2 ml c. 0.5 ml d. 1 ml

a. 0.1 ml

Phenol red is a pH indicator and is: a. Purple/pink at pH 8.4 b. Purple/pink at pH 6.8 c. Purple/pink at pH 2.4 d. Purple/pink at pH 5.4

a. Purple/pink at pH 8.4

Bromocresol purple is a pH indicator and is: a. Yellow at pH 5.2 b. Yellow at pH 6.8 c. Yellow at pH 12.4 d. Yellow at pH 7.4

a. Yellow at pH 5.2

Which of the following refers to specific procedures to prevent un-wanted microorganisms from contaminating a clinical specimen? a. aseptic technique b. needle aspiration c. catheterisation d. disinfection

a. aseptic technique

Biochemical tests are used to determine; a. metabolic activities b. nucleic acid base composition c. amino acid sequences d. staining characteristics

a. metabolic activities

What is the purpose of the citrate test? a. to test if the organism can use citrate as the sole organic source of carbon b. to test if the organism can break down the amino acid tryptophan c. to test if the organism can break down lactose d. to test if the organism can break down xylose

a. to test if the organism can use citrate as the sole organic source of carbon

What is the pore size of the membrane filter used for water quality testing? a. 0.20 µm b. 0.45 µm c. 0.30 µm d. 0.40 µm

b. 0.45 µm

A 10 ml river water sample was membrane filtered. It was found to contain 1 x 103 total coliforms/100ml. How many colonies would have been on the original membrane? a. 1 b. 10 c. 100 d. 1000

b. 10

What volume of 40% KOH is added in the Voges-Proskauer test? a. 500µl b. 200µl c. 100µl d. 600µl

b. 200µl 0.2mL

Following a membrane filtration experiment, a total of 90 colonies were observed growing on a membrane filter used to filter a 1 ml water sample. What is the total C.F.U. per 100ml of water? a. 9 x 102 c.f.u./100ml b. 9 x 103 c.f.u./100ml c. 9 x 106 c.f.u./100ml d. 9 x 104 c.f.u./100ml

b. 9 x 103 c.f.u./100ml

If an antibiotic is classified as being "bacteriostatic" then it is capable of killing bacteria. a. True b. False

b. False

The production of sufficient acid by means of fermentation of glucose will lead to a decrease in pH such that the pH of the medium falls below 4.4. Which of the following tests would be capable of testing for this? a. Indole test b. Methyl red test c. Citrate utilisation test d. Urease test

b. Methyl red test

Which pH indicator is included in the lactose fermentation test? a. Neutral red b. Phenol red c. Methyl red d. Bromocresol purple

b. Phenol red

The pH indicator Phenolphthalein is what colour at a pH of 10? a. Green b. Pink c. Red d. Yellow

b. Pink

Production of acetoin can be detected by which of the following tests? a. Citrate test b. Voges-Proskauer test c. Methyl red test d. Indole test

b. Voges-Proskauer test

19. The presence of 'indicator organisms' in water indicates that? a. Water has been successfully purified and is safe to consume b. Water has been contaminated c. Cryptosporidium is present d. E. coli O157H is present and that the water is unsafe

b. Water has been contaminated

When should an inoculating loop be flame sterilized? a. after transferring the inoculum b. before and after you transfer the culture c. before picking up the inoculum d. at the end of each laboratory class

b. before and after you transfer the culture

Phenol red was the pH indicator included in the amino acid decarboxylase test? a. true b. false

b. false its bromocresol purple

The Vogues Proskaur test uses the same type of medium as the __________ test. a. indole b. methyl red c. lysine decarboxylase d. citrate

b. methyl red

In any bacterial identification scheme, which one of the following procedures must be done before doing biochemical tests? a. prepare a Gram stain of the bacteria b. obtain a pure culture of the bacteria c. examine the bacteria with a microscope d. grow the bacteria on PEA agar

b. obtain a pure culture of the bacteria

Which pH indicator is included in the lactose fermentation test? a. neutral red b. phenol red c. methyl red d. bromocresol purple

b. phenol red

A strain of bacteria underwent an oxidase test. Within 30 seconds a positive oxidase test was observed. What colour would you expect to see? a. blue-green b. yellow c. purple-violet d. no colour change

b. yellow

The BBL CRYSTAL™ Enteric/Nonfermenter (E/NF) kit contains how many different tests? a. 15 b. 20 c. 30 d. 19

c. 30

The BBL CRYSTAL™ Enteric/Nonfermenter (E/NF) kit contains how many different tests? a. 15 b. 20 c. 30 d. 19

c. 30

The IMViC tests consists of how many different tests? a. 7 b. 2 c. 4 d. 5

c. 4

For the membrane filtration experiment, what incubation temperature was used to test a water sample for presumptive faecal coliforms? a. 37°C b. 20°C c. 44°C d. 40°C

c. 44°C

If a species of bacteria is Indole positive, what colour would you expect to see? a. Yellow b. Clear c. Blue-green d. Purple

c. Blue-green

What pH indicator is included in the amino acid decarboxylase test? a. Methyl red b. Bromothymol blue c. Bromocresol purple d. Phenol red

c. Bromocresol purple

A species of bacteria underwent the Hugh and Liefsens test using 2 test tubes. One test tube had no oil added to it, the second test tube had a layer of oil added to ensure no oxygen was available. Following incubation both test tubes were showing a colour change from green to yellow. This means that the species of bacteria being tested is a: a. Oxidiser b. Non-utiliser c. Fermenter d. None of these

c. Fermenter

The IMViC test consists of the following individual tests: a. Indole, methyl red, casein & Voges Proskauer b. Indole, gelatin, casein & Voges Proskauer c. Indole, citrate, methyl red & Voges Proskauer d. Indole, starch, gelatin & Voges Proskauer

c. Indole, citrate, methyl red & Voges Proskauer

Which selective and differential media is used for membrane filtration of water experiment? a. Columbia blood agar b. Eosin methylene blue agar c. Membrane lauryl sulphate agar d. MacConkey agar

c. Membrane lauryl sulphate agar

Which test is routinely used in the dairy industry to ensure that milk has been pasteurised? a. Citrate test b. Methyl red test c. Phosphatase test d. Voges-Proskauer test

c. Phosphatase test

The Indole test helps to identify enteric bacteria based on: a. The ability of the bacteria to produce gas b. The ability of the bacteria to produce acids c. The ability of the bacteria to break down the amino acid tryptophan d. The ability of the bacteria to produce neutral products

c. The ability of the bacteria to break down the amino acid tryptophan

The MIC Value is: a. The highest concentration of an antimicrobial that inhibits growth b. The highest concentration of an antimicrobial that allows growth c. The lowest concentration of an antimicrobial that inhibits growth d. The lowest concentration of an antimicrobial that allows growth

c. The lowest concentration of an antimicrobial that inhibits growth

Once you have sterilized your inoculating loop, it is important that you wait 10-20 seconds before using the loop to pick up a sample from your culture. What is the purpose of letting the inoculating instrument cool off? a. to ensure that you are taking your time and not rushing the transfer to avoid accidents b. to avoid burning the surface of the bench with the inoculating loop when you place it down on the bench top c. to avoid killing the bacterial cells with excess heat d. to avoid over-heating and damaging the instruments

c. to avoid killing the bacterial cells with excess heat

You set up a ten-tube Minimum Inhibitory Concentration test where the concentration of the antibiotic in each tube is a 1/2 dilution of the previous tube. If the concentration of the antibiotic in tube 1 is 3200 micrograms per ml, what is the concentration of the antibiotic in tube 6? a. 3200 µg/ml b. 1600 µg/ml c. 600 µg/ml d. 100 µg/ml

d. 100 µg/ml

What was the starting concentration of Nalidixic acid used for the MIC experiment? a. 32 µg/ml b. 1024 µg/ml c. 512 µg/ml d. 2048 µg/ml

d. 2048 µg/ml

What was the starting concentration of Nalidixic acid used for the MIC experiment? a. 32μg/ml b. 1024μg/ml c. 512μg/ml d. 2048μg/ml

d. 2048μg/ml

What concentration of α-Naphthol is added in the Voges-Proskauer test? a. 1% b. 2% c. 10% d. 5%

d. 5%

The 'Colisure' test allows us to: a. Determine the concentration of ortho-nitro-beta-D-galactoside b. Determine the total coliforms in a 1 ml sample c. Determine the nutrient/carbon source of coliforms in 100 ml d. Calculate the total coliforms present in a 100 ml water sample

d. Calculate the total coliforms present in a 100 ml water sample

What colour change would you expect if a bacterial species is positive for being able to use citrate as its sole carbon source? a. Green to red b. Green to pink c. Blue to green d. Green to blue

d. Green to blue

The amino acid decarboxylation test carried out this term consisted of what two amino acids? a. arginine & glutamine b. lysine & arginine c. leucine & valine d. lysine & ornithine

d. lysine & ornithine

What is the pH indicator included in the selective and differential agar used for membrane filtration examination of water? a. Methyl red b. Phenol red c. Bromocresol purple d. Phenolphthalein

Phenol red?