EXAM

Question 1

What was 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. 0.47 µm

Answer 1

D. 0.45

Question 2

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

Answer 2

B. VOGES-PROSKAUER TEST

Question 3

The volume of 40% KOH added for the Voges-Proskauer test was 300 microlitres:
a. True
b. False

Answer 3

B. FALSE
(0.2ml)

Question 4

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

Answer 4

C. 44

Question 5

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

Answer 5

D. 5%

Question 6

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

Answer 6

C. PHOSPHATASE TEST

Question 7

The amino acid decarboxylation tests carried out this term consisted of what two
amino acids?
a. Arginine & glutamine
b. Lysine & arginine
c. Leucine & valine
d. Lysine & ornithine

Answer 7

D. LYSINE & ORNITHINE

Question 8

A species of bacteria underwent the Hugh and Liefsens test. This was set up in 2
separate test-tubes. One test-tube had a layer of oil covering the media, the other testtube had no oil. Following incubation, both 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

Answer 8

C. FERMENTER

Question 9

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

Answer 9

E. E.COLI PRESENT IN A 100ML WATER SAMPLE

Question 10

What was the volume of the inoculum fluid used with the RapID ONE kit?
a. 4.5 ml
b. 2.5 ml
c. 2 ml
d. 1 ml

Answer 10

D. 1ML

Question 11

What is the Recommended Mandatory Limit Values for FAECAL COLIFORMS
in Bathing water?
a. Less than 1000/100 ml
b. Greater than 1000/100 ml
c. Zero/100 ml
d. 1000/100 ml

Answer 11

A. LESS THAN 1000/100ML

Question 12

What is the name of the carbohydrate that allows membrane lauryl sulphate agar to
be differential?
a. Starch
b. Lactose
c. Glucose
d. Maltose

Answer 12

B. LACTOSE

Question 13

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

Answer 13

B. PHENOL RED

Question 14

Methyl red was the pH indicator used for the amino acid decarboxylase test?
a. True
b. False

Answer 14

B. FALSE

Question 15

How many tests were contained in the commercial RapID ONE biochemical test
kit?
a. 19
b. 18
c. 20
d. 22

Answer 15

A. 19

Question 16

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

Answer 16

D. 2048

Question 17

In the citrate test, before inoculation, the media is green in colour, following
inoculation, what colour change would you expect if a bacteria is positive for being able
to use this citrate as its sole carbon source?
a. Green to red
b. Green to pink
c. Green to yellow
d. Green to blue

Answer 17

D. GREEN TO BLUE

Question 18

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

Answer 18

B. FALSE

Question 19

If a microbe grows well on Membrane Lauryl sulphate (MLS) agar and produces
yellow colonies, you can conclude:
a. the bacteria is most likely Gram positive and ferments lactose
b. the bacteria is most likely Gram positive and does not ferment lactose
c. the bacteria is most likely Gram negative and ferments lactose
d. the bacteria is most likely Gram negative and does not ferment lactose

Answer 19

C. GRAM NEGATIVE AND FERMENTS LACTOSE

Question 20

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

Answer 20

C. LOWEST THAT INHIBITS

Question 21

The volume of bacterial inoculum added in the MIC experiment was 0.2 ml.
a. True
b. False

Answer 21

B FALSE
2ML

Question 22

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

Answer 22

B. WATER HAS BEEN CONTAMINATED

Question 23

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

Answer 23

C. 4
INDOLE
VOGES-PROSKAUER
METHYL-RED
CITRATE UTILISATION

Question 24

Which selective and differential media is used for the membrane filtration of water
experiment?
a. columbia blood agar
b. eosin methylene blue agar
c. membrane lauryl sulphate agar
d. macConkey agar

Answer 24

C. MLS

Question 25

What is the name of 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

Answer 25

B. PHENOL RED

Question 26

The ‘Colisure’ test allows us to: a. determine the concentration of ortho-nitro-beta-D-galactoside b. determine the total coliforms and E. coli present in a 1 ml water sample c. determine the nutrient/carbon source of coliforms in 100 ml d. calculate the total coliforms and E. coli present in a 100 ml water sample

Answer 26

D. COLIFORMS AND E. CLI IN 100ML

Question 27

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

Answer 27

B. FALSE BROMCRESOL PURPLE CRESOL RED

Question 28

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

Answer 28

B PHENOL RED

Question 29

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

Answer 29

D. 600UL 0.6ML

Question 30

A colour change from yellow to cherry red is indicative of a positive Voges Proskauer test? a. true b. false

Answer 30

A TRUE

Question 31

If a scientist wished to test a water sample using membrane filtration for presumptive faecal coliforms they would use an incubation temperature of 37°C: a. true b. false

Answer 31

B FLASE 44C

Question 32

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

Answer 32

C. ABILITY TO BREAK DOWN THE AMINO ACID TRYPTOPHAN

Question 33

Following testing, a sample of water was found to contain between 4-9 coliforms and 0 E. coli per 100ml of water tested, the quality of the water is said to be: a. unsatisfactory b. satisfactory c. excellent d. intermediate

Answer 33

A UNSATISFACTORY

Question 34

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

Answer 34

D. ALL OF THE ABOVE

Question 35

If a species of bacteria is Indole positive, what colour would you expect to see develop? a. Yellow b. No colour c. Blue-green d. red

Answer 35

d. red

Question 36

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

Answer 36

B. METHYL-RED