Second year B. Pharm. (III semester) 2020-21
Subject Name: - Pharmaceutical Microbiology
Multiple Choice Questions : Unit II
1. The differential staining technique was discovered by....
a.Dr.christian Gram in 1884
b.Robert Hook
c.Louies posture
d.Robert Koch
Ans. a
Reason- The differential staining technique was discovered by Dr.christian Gram in 1884
2.which of the following is the example of Gram negative bacteria ?
a.Lactobacillus
b.Eschericia coli
c.staphylococcus aures
d.Bacillus subtilis
Ans.b
Reason- Escherichia coli is the example of Gram negative bacteria. Others are example of Gram
positive bacteria .
3.what is the correct order of staining reagents in Gram staining
a.crystal violet, alcohol, iodine solution, safranin
b.crystal violet, iodine solution, alcohol, safranin
c. Crystal violet, safranin , alcohol, iodine solution
d. Iodine solution, crystal violet, alcohol, safranin
Ans. b
Reason- Gram staining is a type differential staining technique. In this process the fixed bacterial
smear is subjected to the following staining reagents in the order listed as: crystal violet, iodine
solution, alcohol, (decoloursing agent) and safranin .
4.The dye eosinate of methylene blue belongs to which group?
a.Acidic dye
b.basic dye
c.Neutral dye
d.oxazine dye
Ans- c.
Reason. A neutral due is complex salt dye acid with dye base so eosinate of methylene blue is an
example of neutral dye. A acidic dye is negative and basic dye is positive
5) Who discovered gram staining?
a)Paul ehrlich
b) Christian gram
C) Ernst ruskan
d) Leeuwenhoek
Ans. B
Reason-The gram staining method, named after the danish bacteriologist who originally devised
it in 1882(published 1884) Christian gram, is one of the most important staining technique in
microbiology.
6) The gram staining technique differentiate bacteria on the basis of.
a) Cell wall composition
b) Due to gram's iodine
c) Action of acetone
d) Action of safranin
Ans. A
Reason-gram staining is a common technique used to differentiate two large groups of bacteria
based on their different cell wall constituents.
7) Iodine is used as
a) Fixative
b) Mordant
c)Stain
d) Solubiliser
Ans. B
Reason-iodine is used to treat and prevent iodine deficiency and as an antiseptic.
8) Gram staining is an example of
a) acid fast stain
b) acid stain
c) differential stain
d) non of these
Ans. C
Reason-the gram stain is a differential staining technique that allow scientists to detect
differences in bacteria based on the variable structure of the bacterial cell.
9) Which is used in gram staining
a) crystal violet
b) acetone
c)water
d) all of these
Ans. D
Reason-gram staining involves 3 processes-staining with a water soluble dye called crystal
violet, decolonization and counterstaining usually with safanin.
10) The stain which differentiates two group of bacteria in a mixture is know as
a) negative stain
b) simple stain
c) differential stain
d) indirect stain
Anc. C
Reason-gram stain or gram staining also called grams method, is a method of staining used to
distinguish and classify bacterial species into two large groups gram positive bacteria and gram
negative bacteria.
11.stains are organic compound containing
a. Benzene ring
b. Chromophore
c. Auxochrome group
d. All of above
Ans:d
Reason: benzene ring with chromophore and auxochrome group forms a stain.
12.In acid fast staining, which reagent is not used?
a. Primary stain
b. Decolonizing agent
c. Mordant( Gram's iodine)
d. Counter stain
Ans: c
Reason: Mordant ( Gram's iodine) reagent used in Gram staining technique.
13.In the following, which statement is wrong?
a. Acid fast staining is bacterial smear is stained with a single stain
b. Capsule staining is used to detect presence of capsule surrounds to cell.
c. Flagella stain is used to detect presence and arrangement of flagella
d. Gram staining is used for differentiation and identification of bacteria
Ans: a
Reason: because acid fast staining is used for differential staining procedure in bacteriology.
14.The complex of crystal violet iodine magnesium ribonucleate [CV-l mg ribonucleate ] is not
formed in Gram negative bacteria.
a. True
b. False
Ans:a
Reason: because mg- ribonucleate is absent in cell wall hence [ CV l complex] is formed in
Gram negative bacteria.
15.The science of classification of bacteria is called
a.Morphology
b.bacteriology
c.Taxonomy
d.none of this
Ans:c
Reason: the science which deals with classification of bacteria is called Taxonomy
16) In pharmaceutical industry and research Institutes are constantly screening ____.
a. Soil
b. Water
c. Marine samples
d. All of the above
Ans- d. All of the above
Reason:- to isolate new antibiotic enzymes and vitamins producing microorganisms.
17) The science of classification is called____.
a. Taxonomy
b. Bacteriology
c. Microbiology
d. Biology
Ans:- a. Taxonomy
Reason:- the branch of science concerned with classification, especially of organisms.
18) The relationship of microorganisms in each section is based on___ characteristics.
a. Morphology
b. Staining reactions
c. Nutritional requirements
d. Physiological properties
e. All of the above
Ans- e.All of the above
19) In recent years microorganisms have been identified and classified on the basic of ____.
a. Biochemical tests
b. Genetic makeup
c. Staining reactions
d. None of these
Ans- b. Genetic makeup.
20)Which of the following cell shows resistant to decolourisation on application of decolourising
agent
a.Non acid fast
b.Acid- fast
c.Both a & b
d.None of these
Ans:b
Reason:Cellular waxes are present in acid fast cells so primary stain is more soluble in cellular
waxes than decolourising reagent.
21) The primary stain of gram staining is.......
a.Carbol fuchsin
b.Gram's iodine
c.Crystal violet
d.Both a & c
Ans:c
Reason:Crystal violet/Indian ink stain is used first and stain all cells deep violet in colour in gram
staining .Carbol fuchsin is also primary stain but it used in acid fast staining.
22)Which of the following is not gram positive bacteria
a.Bacillus anthrasis
b.Staphylococcus
c.Kelbsiella pneumoniae
d.Clostridium tetani
Ans: c
Reason:Kelbsiella pneumoniae is gram negative bacteria .
23)Acid fast staining was independently proposed by.......
a.Ziehl and Neelsen
b.Robert koch
c.Dr.Christian Gram
d.None of these
Ans:a
Reason:Ziehl and Neelsen proposed acid fast staining in 1882-1883.
24)The percentage of acid alcohol in acid fast staining is.....and....
a.3 and 95%
b.95and 3%
c.9 and 100%
d. None of these
Ans: a
Reason:The percentage of acid alcohol in acid fast staining is a very intensive decolouriser
25)In which method carbol fuchsin is used as primary stain
a.Acid fast staining
b.Gram staining
c.Negative staining
d.Both a & b
Ans:a
Reason:Carbol fuchsin is lipid soluble and contains phenol which helps the stain to penetrate
the cell wall.
26)Crystal violet iodine complex is formed in........bacteria
a.Gram positive
b.Gram negative
c.Both a and b
d.None of above
Ans:b
Reason:In gram positive bacteria CV- I- Mg ribonucleate complex is formed but in gram
negative Mg-ribonucleate is absent in cell wall so only CV-I complex is formed.
27) Classify the following as acidic and basic stain.
1.Methylene blue
2.Eosin
3.Nigrosin
4.Crystal violet
A. Acidic-1, 4 .Basic -2, 3
B. Acidic-2, 3 . Basic-1, 4
C. Acidic-1, 3.Basic-2, 4
D. Acidic-2, 4. Basic-1, 3
Ans. Correct option is B
28) Bacteria that are difficult to stain can be satined by using....... Staining
A. Gram staining
B. Negative staining
C. Simple staining
D. All of them
Ans. B
Reason. In negative staining, no need of heat fixation as well as no physical or chemical
treatment are required
29) Odd one out
Eosin, methylene blue, carbol fuchsin, crystal violet
Ans Eosin
Reason. Other are basic stain
30) select the statement regarding .
A. This is a widely used technique.
B. Discovered by Dr. Gram
C. Also called as differential technique.
D. Can not used for differentiation of gram positive and negative bacteria
Ans. D.
Reason. This technique is used for differentiation of gram positive and negative bacteria.
31.What is the correct order of staining reagent in Gram-Staining?
A. Crystal Violet, Alcohol, Iodine solution, Safranin
B. crystal Violet, Iodine solution, Alcohol, Safranin
C.Crystal violet,Safranin,Alcohol, Iodine solution
D. Iodine solution, Crystal Violet, Alcohol
egative bacteria.
31.What is the correct order of staining reagent in Gram-Staining?
A. Crystal Violet, Alcohol, Iodine solution, Safranin
B. crystal Violet, Iodine solution, Alcohol, Safranin
C.Crystal violet,Safranin,Alcohol, Iodine solution
D. Iodine solution, Crystal Violet, Alcoho
Reason= Gram staining is a type of differential staining. In order Crystal Violet, Iodine solution,
Alcohol (Decolorizing agent) and Safranin.
32.Which of the following is commonly used in Gram-Staining?
A. Carbon Fuschin
B. Ethyl Alcohol
C. Crystal Violet
D. None of these
Ans. C
Reason= Crystal Violet is basic stain and treated with Iodine - potassium mixture to fix stain.
33. Which of the following is the example of Gram negative Bactria?
A. Lactobacillus
B. Escherichia coli
C. Staphylococcus aureus
D. Bacillus substilis
Ans. B
Reason= Escherichia coli is example of gram negative Bactria. Others are all examples of gram
positive bacteria.
34. Gram staining was developed by
A. Louis pasteur
B. Antoni Van Leeuwenhoek
C. Robert koch
D. Christian gram
Ans. D
35. Gram staining is an example of
A. Acid fast stain
B. Acid stain
C. Differential stain
D. None of these
Ans. C
Reason= Gram staining is one of the most fundamental and widely used for differential and
identification of bacteria.
36.Gram staining was developed in
A. 1882. B. 1883
C. 1884. D. 1885
Ans. C
Reason= Gram staining discovered by Christian Gram in 1884
37. Counter stain used in Gram staining is
A. Safranin
B. Crystal Violet
C. Carbol Fuschin
D. Acetocarmine
Ans. A
Reason= becz, this is the final reagent to stain red, cells have decolorized.
38. In Gram-Staining Iodine is used as a
A. Fixative
B. Mordant
C. Solubiulizer
D. Stain
Ans. B
Reason= Mordant is any substance that forms an insoluble compounds with stain and to fix the
colour to bacterial cells
39. State true or false
I) Autoclaving is a process of instrument sterilization that uses time, temperature and pressure to
kill all forms of microbial life
a) True
b) False
Ans: a- True
Above statement is true.
II) Dry heat sterilization usually takes about an hour or so at 530 F or 2 hour at 420 F.
a) True
b) False
Ans: b- false
Dry heat sterilization usually takes place about an hour or so at 340 F or 2 hours at 320 F.
40. Following is not a example of gaseous sterilization.
a) Formaldehyde
b) Ethylene oxide
c) Phenol
d) Both a and b
Ans: c
formaldehyde and Ethylene oxide are an example of gaseous sterilization but phenol is an
example of use of disinfectants in chemical materials.
41. Gram-negative bacteria are identified by........
a) IMViC Test
b) citrate Test
c) Methyl red Test
d) None of above
Ans: a
IMViC are a group of individual tests used in microbiology laboratories for identification and
classification of an organism.
42. Glassware used in microbiology laboratories are sterilised by ........
a) Autoclave
b) Dry heat sterilization
c) Hot air oven
d) All of above
Ans: c
Hot air oven is used in microbiology laboratories for sterilization purpose ( for 2-4 hours at
130*-170*C)
43. In autoclave,the principle involved is........
a) Dry heat
b) Steam under pressure
c) Moist heat
d) Only option b and c
Ans: d
Moist heat and steam under pressure is used to sterilize the material present inside the chamber
44. The term 'IMViC' is an acronym for each of these tests........
a) I- indole test, M- menthol test, V- Vages-proskauer test, C- citrate test
b) I- iodine test, M- menthol test, V- Vages-proskauer test, C- Chloride test
c) I- indole test, M- methyl red test, V- Vages-proskauer test, C-citrate test
d) I- Iron test, Methyl test, V-Vages-proskauer test, C-citrate
Ans: c
IMViC are a group of individual tests....
I- indole test
M- methyl red test
V- Vages-proskauer test
C- citrate test
45). Following is a example of gaseous sterilization.
a) Formaldehyde
b) Ethylene oxide
c) Phenol
d) Both a and b
Ans: d
formaldehyde and Ethylene oxide is an example of gaseous sterilization
46) The different staining techniques was discovered by...... in 1884
a) Dr. Christian Gram
b) Marry Mallon
c) Osborne Gram
d) Both a and c
Ans- (a), Dr.Christain Gram discovered different staining techniques in 1884.
47) Stains are organic compounds containing......
a) Chromophore
b) Oxygen
c) Benzene ring
d) option a and c
e) None of above
Ans- (d), Benzene ring with Chromophore and auxochrome group forms a stain, oxygen is not
used.
48) Match the following temperature and time relationship for hot air oven
Temperature Time
A) 170 I) 150
B) 160 II) 180
C) 150 III) 60
D) 140 IV) 120
a) A- III, B- IV, C- I, D-II
b) A- VI, B- II, C- I, D- III
c) A- I, B- II, C-III, D- IV
d) A- III, B- I, C- II D- IV
Ans- (a)
49) long form of TDT is......
a) Thermal Density Time
b) Thermal Death Time
c) Time death Thermal
d) None of above
Ans- (b) Thermal Death Time is a right answer,TDT is how long it takes to kill specific
bacterium at specific temperature.
50) .......is the sterilizing agent
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Ethylene oxide
Ans- (d) Ethylene oxide is a low temperature gaseous process widely used to sterilize a variety of
health care products.
51) Match the following related to class of moist heat sterilization.
Temp. Method
1.below at P. Autoclave
100*C method
2. At 100*C Q.Pasteurization
3.above R. Tyndallization
100*C
A. 1-P, 2-R, 3-Q
B. 1-Q, 2-P, 3-R
C. 1-Q, 2-R, 3-P
D. 1-P, 2-Q, 3-R
Ans-correct option is C
52) In indole production tryptophan is converted into indol in presence of______enzyme
A. Reductase
B. Citrase
C. Tryptophanase
D. None of them
Ans. C
Reason. Reductase us used in nitrate reduction test, while citrase is used in Oxaloacetic acid
production
53) odd one out
UV radiation, X-Ray, Gamma ray, Cathode ray
Ans. UV radiation
Reason. Other are ionizing radiations
54) In urease test Christensen medium contain_______
A. Urea and methyl red indicator
B. Urea and phenol red indicator
C. Methyl red and phenol red indicator
D. All of them
Ans. B
Reason. As the name indicate it contains urea and phrlenol red indicator
55) The type of radiation which interface in DNA replication is ________
A. X-Ray
B. Cathode ray
C. UV ray
D. Gamma ray
Ans. C
Reason. UV ray induce the production of abnormal nucleotide such as thymine dimer which
interface DNA replication.
56) Stains is an organic compounds containing a benzene ring with ____.
a. Chromophore
b. Auxochrome
c. Both a & b
d. None of these
Ans- c. Both a & b.
Reason:- Auxochrome ionizes the chromogen, gives it a charge. This helps the chromogen form
salts and bind to substances like tissues or fibers.
57) Which of the following is an example of Basic Dyes?
a. Eosin
b. Safranine
c. Congo red
d. Nigrosin
Ans- b. Safranine
Reason:- Except Safranine, all are the examples of Acidic dyes.
58) Acid fast staining is also known as Ziehl-Neelsen staining.
a. True
b. False
Ans:- a.True
Reason:- Ziehl–Neelsen staining is a bacteriological stain used to identify acid-fast organisms.
59) Which of the following Biochemical test for Bacteria?
a. Indole production
b. Methyl red
c.Vogas-Proskauer
d. Citrate utilisation
e. All of the above
Ans:- e. All of the above
Reason:- Because "I" is for indole test; "M" is for methyl red test; "V" is for Voges-Proskauer
test, and "C" is for citrate test.
60.sterilization is...
A.process of growing microbes in laboratory
B. Process for preparation of antibiotics
C. Killing or removing all the microorganisms
D.fot preparation of tablets
Ans.C
Reason. Sterilization is process to kill or removing all the microorganisms
61.Brown tubes on exposure to temperature 121degree C changes color from?
A.Red to green
B.Brown to Orange
C.green to Brown
D.yellow to red
Ans.A
Reason . In Brown tubes color changes red through yellow brown to green
62 In sterility indicators the chemical indicators are..
A.Brown tubes
B.witness tubes
C.Heat sensitive tape
D.all of the above
Ans.D
63.In death rates or survivor curvethe terms used for expression of resistance is ...
A.D -value
B.Z -value
C.F - value
D.all of the above
Ans.D
64.which of the following is not physical indicators?
A.moist heat
B.dry heat
C.Radio sterilization
D.Brownes tubes
Ans.D
Reason. Brown's tubes are chemical indicators
65. Following are the three parameters of steam sterilization........
a) Steam under pressure, temperature, time.
b) Concentration, temperature, time.
c) Temperature,Time, atmospheric pressure.
d) Time, concentration, steam under pressure.
Ans: a.
Steam under pressure, temperature and time these are the three parameters of steam sterilization.
66. Type III Browne's tube shows........ colour indicator at temperature ........*C.
a) Black spot, 170
b) Green spot, 160
c) Red spot, 80
d) Blue spot, 100
Ans: b.
Type III Browne's tube shows Green spot colour of indicator at temperature 160*C.
67. The Royce sachet is a chemical indicators for......... Sterilization.
a) Magnesium oxide
b) Methyl chloride
c) Ethylene oxide
d) None of above
Ans: c.
The Royce sachet is a chemical indicators for ethylene oxide sterilization.
68. Time in minute at any defined temperature to destroy 90% viable microorganism is call........
a) F- value
b) Z- value
c) T- value
d) D- value
Ans: d.
D- value or decimal reduction time is the time required, at a given condition to achieve a log of
reduction, that is, to kill 90% of relevant microorganism.
69. The absence of all forms of microbial life,is known as........
a) Disinfection
b) Sanitization
c) monitration
d) Both a and b
e) Sterility
Ans: e.
Sterility is a the freedom from the presence of viable microorganism.