1.
2.
3.
4.
5.
The phospholipids present in cytoplasm membrane of the archaeo-bacteria is
A.
phosphoglycerides
B.
polyisoprenoid
C.
polyisoprenoid branched chain lipids
D.
none of the above
The oldest eukaryotic organisms are considered to be
A.
diplomonads like Giardia
B.
archaea
C.
fungi
D.
animals
The phospholipids present in cytoplasm membrane of eubacteria is mainly
A.
phosphoglycerides
B.
polyisoprenoid
C.
phospholipoprotein
D.
none of these
Which were the investigators lived at the same time?
A.
Koch and Pasteur
B.
Darwin and Woese
C.
Van Leeuenhoek and Ricketts
D.
Berg and Hooke
The unifying feature of the archaea that distinguishes them from the bacteria is
A.
habitats which are extreme environments with regard to acidity
B.
absence of a nuclear membrane temperature
1
6.
7.
8.
9.
C.
presence of a cell wall containing a characteristic outer membrane
D.
cytoplasmic ribosomes that are 70S
Mycoplasmas are different from the other prokaryotes by
A.
presence of chitin in cell walls
B.
presence of murrain in cell walls
C.
presence of proteins in cell walls
D.
absence of cell wall itself
Evolutionary relationships between groups of organisms are determined using which of
the following type of information?
A.
Comparisons of nucleotide sequences
B.
Comparisons of biochemical pathways
C.
Comparisons of structural features
D.
All of the above
Which of the following is not true for eukaryotic cells?
A.
Nucleus is bounded by nuclear membrane
B.
Chromosomes contain histones
C.
Chloroplasts and mitochondria contains 70S ribosomes
D.
Gas vacuoles are present
Which of the following is not true for prokaryotic organism?
A.
Nucleus is not bounded by nuclear membrane
B.
Chromosomes does not contain histones
C.
80S ribosomes are distributed in cytoplasm
D.
Cell wall contains peptidoglycan as one of the major component
2
10. Gram staining was introduced by
A.
Christian gram
B.
Alfred Gram
C.
Robertcook
D.
Louis Pasteur
11. Which of the following is considered the most unifying concept in biology?
A.
Taxonomy
B.
Anatomy
C.
Genetics
D.
Evolution
12. Various bacterial species can be subdivided into
A.
subspecies
B.
biovarieties
C.
serovarieties
D.
all of these
13. Living organisms have many complex characteristics. Which one of the following is
shared by non-living matter as well?
A.
Homeostasis
B.
Tissues
C.
Reproduction
D.
Molecules
14. A newly discovered microscopic structure is hypothesized to be a living organism.
Which of the following lines of evidence would support the contention that this
organism may be alive?
A.
It contains DNA
B.
It is made of a single cell
C.
It utilizes energy
D.
All of these
15. Mycoplasmas, rickettsiae, and chlamydiae are
A.
types of fungi
3
B.
small bacteria
C.
species of protozoa
D.
forms of viruses
16. Which of the following structure is absent in eukaryotic cells?
A.
Mitochondria
B.
Chloroplasts
C.
Golgi structure
D.
Mesosome
17. Who was the inventor of the Petri dish?
A.
R.J. Petri, an assistant of R. Koch
B.
A famous French cook
C.
Italian glass blower from Petri, Italy
D.
None of the above
18. Which one is not studied in microbiology?
A.
Bacteria
B.
Animal behaviour
C.
Fungi
D.
Algae
19. A characteristic of protein synthesis in both the archaea and eukarya is
A.
transcription and translation are coupled
B.
translation is inhibited by diphtheria toxin
C.
proteins are synthesized from D-, rather than L-, isomers of amino acids
4
D.
the initiator tRNA is charged with N-formyl-methionine
20. Cell theory includes all of the following except
A.
all organisms are composed of one or more cells
B.
the cell is the most primitive form of life
C.
the cell is the structural unit of life
D.
cells arise by division of preexisting cells
21. The five-kingdom system of classification was set up by
A.
Louis Pasteur
B.
Robert Whittaker
C.
Robert Koch
D.
Masaki Ogata
22. The membranes of which domains are chemically the most similar?
A.
Archaea and Bacteria
B.
Bacteria and Eukarya
C.
Eukarya and Archaea
D.
membranes of all three domains are chemically identical
23. Primary differences between cilia and flagella are
A.
arrangement of microtubules
B.
length and location of basal bodies
C.
how the microtubules are fused to each other
D.
number, length and direction of force
24. All membranes of free-living organisms have phospholipid bilayers, but exception is
A.
bacteria
B.
5
fungi
C.
archaea
D.
protozoa
25. All of the following are features of prokaryotes except
A.
nitrogen fixation
B.
photosynthesis
C.
sexual reproduction
D.
locomotion
26. Which of the following structures is the smallest?
A.
Viriod
B.
Hydrogen atom
C.
Bacterium
D.
Mitochondrion
27. Which of the following is/are included in Kingdom Prokaryotae?
A.
Bacteria
B.
Protozoa
C.
Fungi
D.
All of these
28. Which of the following may account for the small size of the cells?
A.
The rate of diffusion
B.
The surface area/volume ratio
C.
The number of mRNAs that can be produced by the nucleus
D.
All of the above
29. Genetic and biochemical similarities between contemporary cyanobacteria and
eukaryotic chloroplasts are accepted to mean that
6
A.
eukaryotes evolved from bacteria
B.
eukaryotes evolved from archaea
C.
oxygenic photosynthesis first evolved in eukaryotes
D.
cyanobacteria arose from chloroplasts which escaped from plant cells
30. Which of the following best represents the hierarchy of levels of biological
classification?
A.
Phylum, kingdom, class, order, genus, species, family
B.
Kingdom, phylum, class, order, family, genus, species
C.
Kingdom, phylum, family, class, order, genus, species
D.
Class, order, kingdom, phylum, family, genus, species
31. The three domain version of life on earth is based on the
A.
nucleic acid sequence data
B.
morphological traits
C.
metabolic traits
D.
characteristics of the cell wall
32. The foundation for the germ theory of disease was set down by
A.
Robert Koch
B.
Ronald Ross
C.
Louis Pasteur
D.
Walter Reed
33. Most microbial structures and enzymes are composed of
A.
lipids
B.
proteins
7
C.
carbohydrates
D.
lipids and carbohydrates
34. The individual best remembered for bringing microbes to the world is
A.
Robert Hooke
B.
Antony Van Leeuenhoek
C.
Robert Koch
D.
Masaki Ogata
35. Micro organisms are found in which of the following kingdom of five kingdom concept
(Whittaker's classification)?
A.
Monera
B.
Protista
C.
Fungi
D.
All of these
36. The first organism in most natural food chains is
A.
a herbivore
B.
a decomposer
C.
photosynthetic
D.
carnivorous
37. The third kingdom, protista, as suggested by E.H. Haeckel includes
A.
bacteria
B.
algae
C.
fungi
8
D.
all of these
38. Eukaryotic cell organelles first emerged
A.
from a specialized lineage of cells within the kingdom Protista
B.
when prokaryotes engulfed each other and became interdependent
C.
when bacteria made their first attempts at reproduction
D.
just before the origin of the animal and fungal kingdoms
39. Who discovered the bacteria that cause cholera?
A.
Pierre Berthelot
B.
Robert Koch
C.
Louis Pasteur
D.
Rudolf Virchow
40. Prokaryotic microorganism include
A.
protozoa
B.
fungi
C.
bacteria
D.
all of these
41. All the following are basic properties of cells except
A.
cells have nuclei and mitochondria
B.
cells have a genetic programme and the means to use it
C.
cells are capable of producing more of themselves
D.
cells are able to respond to stimuli
42. Which of the following microorganisms is classified as a member of archaebacteria?
9
A.
Gyanobacteria
B.
Methanobacteria
C.
Trichomonads
D.
Mycoplasma
43. The idea of selective toxicity was first proposed by
A.
Antony van Leeuwenhoek
B.
Paul Ehrlich
C.
Louis Pasteur
D.
Alexander Fleming
44. Which of the following sequences has helped in identifying eukaryotes, eubacteria and
archeabacterial cell types?
A.
Signature sequence
B.
Signal sequence
C.
Shine-Dalgarno sequence
D.
Amino acid sequence
45. Archeal cells usually do not contain peptidoglycan, rather contain pseudopeptidoglycan which is mainly composed of
A.
N-acetylmuramic acid and L-amino acids
B.
N-acetylmuramic acid and D-amino acids
C.
N-acetyltalosaminuronic acid and D-amino acids
D.
N-acetyltalosaminuronic acid and L-amino acids
46. In the three domain system of classification, the traditional bacteria are placed in the
A.
eukarya
B.
archaea
C.
eubacteria
D.
none of these
10
47. One of the reasons for the evolutionary success of the kingdom Monera is that its
members are nutritionally diverse. Which of the following(s) is/are the way(s) of
obtaining energy?
A.
Photoautotrophy
B.
Photoheterotrophy
C.
Chemoheterotrophy
D.
All of the above
48. Carl Woese and his colleague are best known for establishing
A.
the five kingdom system
B.
the three domain system
C.
the prokaryote-eukaryote system
D.
the plant-animal system
49. Which of the following is not found in the kingdom Monera?
A.
Organelles
B.
Organized cell structure
C.
Ability to reproduce
D.
Ability to use energy
50. Which of the following is the most primitive?
A.
Virus
B.
Eukaryote
C.
Archaeon
D.
Mitochondria
51. All the following are considered eukaryotes except
A.
archaea
B.
fungi
C.
protozoa
D.
humans
52. Which cell type is considered to have the oldest ancestor?
11
A.
Archaea
B.
Bacteria
C.
Eukarya
D.
they all share the same ancestor
53. What is Mycology?
A.
Study of viruses
B.
Study of nucleic acid
C.
Study of bacteria
D.
Study of fungi
54. Which of the following organelles contain DNA, divides and possesses some degree of
autonomy?
A.
Golgi apparatus
B.
Ribosome
C.
Chloroplast
D.
Peroxisomes
55. All of the following individuals contributed to cell theory except
A.
Robert Hooke
B.
Matthias Schleiden
C.
Theodor Schwann
D.
Rudolf Virchow
56. Eukaryotic micro organisms include
A.
protozoa
B.
fungi
12
C.
algae
D.
all of these
57. The binomial name of a microbe is composed of
A.
its kingdom and genus names
B.
its genus name and a species modifier
C.
its family and class names
D.
its genus and species names
58. Which of the following is a characteristic unique to the ciliates?
A.
Use of cilia as a sensory function
B.
Presence of both a macronucleus and several micronuclei
C.
Both (a) and (b)
D.
Possess a light-detecting eye spot
59. Which of the following structure is present in prokaryotic cells?
A.
Mitochondria
B.
Chloroplasts
C.
Golgi structure
D.
Mesosome
60. The word cell was first used by
A.
Robert Hooke
B.
Theodor Schwann
C.
Louis Pasteur
D.
Ronald Ross
61. What are Blue-Green bacteria called?
A.
Acquaobacteria
13
B.
Cyanobacteria
C.
Protozoa
D.
None of the above
62. The endosymbiosis hypothesis provides an explanation for how
A.
eukaryotes developed from prokayotes
B.
prokaryotes developed from eukaryotes
C.
algae developed from protozoa
D.
protozoa developed from algae
63. The Archaea include all of the following except
1.
2.
3.
A.
methanogens
B.
halophiles
C.
thermoacidophiles
D.
cyanobacteria
Which of the following bacteria lack a cell wall and are therefore resistant to penicillin?
A.
Cyanobacteria
B.
Mycoplasmas
C.
Bdellovibrios
D.
Spirochetes
A cluster of polar flagella is called
A.
lophotrichous
B.
amphitrichous
C.
monotrichous
D.
petritrichous
Flagella move the cell by
A.
many flagella beating in a synchronous, whip-like motion
B.
an individual flagellum beating in a whip-like motion
C.
spinning like a propeller
D.
attaching to nearby particles and contracting
14
4.
5.
6.
7.
8.
9.
The protein from which hook and filaments of flagella are composed of, is
A.
keratin
B.
flagellin
C.
gelatin
D.
casein
The cooci which mostly occur in single or pairs are
A.
Streptococci
B.
Diplococci
C.
Tetracocci
D.
None of these
Which of the following may contain fimbriae?
A.
Gram-positive bacteria
B.
Gram-negative bacteria
C.
Both (a) and (b)
D.
None of these
Peptidoglycan accounts for __________ of the dry weight of cell wall in many gram
positive bacteria
A.
50% or more
B.
About 10%
C.
11%+ 0.22%
D.
About 20%
Bacteria having no flagella are unable to
A.
move
B.
reproduce
C.
stick to tissue surfaces
D.
grow in nutrient agar
Which of the following is true about cell wall of gram-positive bacteria?
15
A.
It consists of multiple layers
B.
It is thicker than that associated with gram-negative bacteria
C.
It contains teichoic acids
D.
All of these
10. The cell walls of many gram positive bacteria can be easily destroyed by the enzyme
known as
A.
lipase
B.
lysozyme
C.
pectinase
D.
peroxidase
11. The cell wall of
A.
gram-positive bacteria are thicker than gram-negative bacteria
B.
gram-negative bacteria are thicker than gram-positive bacteria
C.
both have same thickness but composition is different
D.
none of these
12. Peptidoglycan is also known as
A.
N-acetyl muramic acid
B.
murein mucopeptide
C.
N acetylglucosamine
D.
mesodiaminopimetic acid
13. Genetic system is located in the prokaryotes in
A.
nucleoid
B.
chromatin
C.
nuclear material
D.
all of these
14. Which is most likely to be exposed on the surface of a gram-negative bacterium?
16
A.
Pore protein (porin)
B.
Protein involved in energy generation
C.
Lipoteichoic acid
D.
Phospholipids
15. The last step in synthesis of peptidoglycan is
A.
attachment of a peptide to muramic acid
B.
attaching two amino acids to form a cross-link
C.
attachment of a portion of peptidoglycan to a membrane lipid
D.
binding of penicillin to a membrane protein
16. Cytoplasmic inclusions include
A.
ribosomes
B.
mesosomes
C.
fat globules
D.
all of these
17. The cocci which forms a bunch and irregular pattern are
A.
Staphylococci
B.
diplococci
C.
Tetracocci
D.
Streptococci
18. Chemotaxis is a phenomenon of
A.
swimming away of bacteria
B.
swimming towards a bacteria
C.
swimming away or towards of bacteria in presence of chemical compound
D.
none of the above
19. The structure responsible for motility of bacteria is
17
A.
pilli
B.
flagella
C.
sheath
D.
capsules
20. The next to last step in peptidoglycan biosynthesis is
A.
synthesis of the NAM-peptide subunit
B.
removal of the subunit from bactoprenol
C.
linking the sugar of the disaccharide-peptide unit to the growing
peptidoglycan chain
D.
cross-linking the peptide side chains of peptidoglycan
21. The cocci which forms a chain is
A.
Streptococci
B.
diplococci
C.
Staphylococci
D.
Tetracocci
22. The arrangement, in which flagella are distributed all round the bacterial cell, is known
as
A.
lophotrichous
B.
amphitrichous
C.
peritrichous
D.
monotrichous
23. Periplasm is
A.
the area between the inner and outer membranes of gram-negative bacteria
B.
the area between the inner and outer membranes of Gram-positive bacteria
C.
the interior portion of mitochondria
D.
the area outside the cell membrane that is influenced by the polymers
24. Which of the following has peptidoglycan as a major constituent of cell wall?
A.
Gram-negative bacteria
B.
Gram-positive bacteria
C.
Fungi
18
D.
None of these
26. The bacteria deficient in cell wall is
A.
Treponema
B.
Mycoplasma
C.
Staphylococcus
D.
Klebsiella
27. Which of the following is not true about peptidoglycan?
A.
It is a polymer consisting of N-acetyl glucosamine, N-acetyl muramic acid
and amino acids (alanine, lysine, etc.)
B.
It is present in prokaryotic cell wall
C.
It occurs in the form of a bag shaped macro molecule surrounding the
cytoplasm membrane
D.
None of the above
28. The common word for bacteria which are spherical in shape is
A.
cocci
B.
bacilli
C.
spirilla
D.
pleomorphic
29. Single or clusters of flagella at both poles is known as
A.
monotrichous
B.
petritrichous
C.
amphitrichous
D.
none of these
30. Which of the following bacterial genera (that produces endospore) have medical
importance?
A.
Clostridium
19
B.
Bacillus
C.
Both (a) and (b)
D.
None of these
31. Microcapsules are composed of
A.
proteins
B.
polysaccharides
C.
lipids
D.
all of these
32. Gram positive cells have a
A.
second outer membrane that helps to retain the crystal violet stain
B.
multiple layer of peptidoglycan that helps to retain the crystal violet stain
C.
thick capsule that traps the crystal violet stain
D.
periplasmic space that traps the crystal violet
33. The common word for bacteria which are straight rod in shape is
A.
cooci
B.
bacilli
C.
spirilla
D.
pleomorphic
34. A single polar flagella is known as
A.
monotrichous
B.
lophotrichous
C.
amphitrichous
D.
none of these
35. Teichoic acids are typically found in
20
A.
cell walls of gram positive bacteria
B.
outer membranes of gram positive bacteria
C.
cell walls of gram negative bacteria
D.
outer membranes of gram negative bacteria
36. In eukaryotic cells, ribosomes are
A.
70S
B.
60S
C.
80S
D.
Not specific
37. Porins are located in
A.
the outer membrane of gram-negative bacteria
B.
the peptidoglycan layer of gram-positive bacteria
C.
the cytoplasmic membrane of both gram-negative and gram-positive
bacteria
D.
the periplasmic space of gram-negative bacteria
38. Which of the following is exposed on the outer surface of a gram-negative bacterium?
A.
O-antigen of lipopolysaccharide (LPS)
B.
Polysaccharide portion of lipoteichoic acid (LTA)
C.
Braun lipoprotein
D.
Electron transport system components
39. Which of the following does not contain protein?
A.
Pili
B.
Flagellum
21
C.
Lipoteichoic acid
D.
Porin
40. Swimming towards a chemical of bacteria is termed as
A.
positive chemotaxis
B.
negative chemotaxis
C.
phototaxis
D.
magnetotaxis
41. Chemically the capsule may be
A.
polypeptide
B.
polysaccharide
C.
either (a) or (b)
D.
none of these
42. Peptidoglycan is found only in the bacterial
A.
cell membrane
B.
glycocalyx
C.
cell wall
D.
spore
43. The cell walls of Gram positive bacteria contain two modified sugar, viz. Nacetylgucosamine (NAG) and N- acetylmuramic acid (NAM). They are covalently linked
by
A.
α- 1,4-glycosidic bond
B.
β-1,6-glycosidic bond
C.
α- 1,6-glycosidic bond
D.
β- 1,4-glycosidic bond
22
46. The location where the bacterial chromosome concentrates is called
A.
nucleus
B.
nuclein
C.
nucleoid
D.
nucleose
47. Which of the following is analogous to mesosomes of bacteria?
A.
Mitochondria of eukaryotes
B.
Golgi apparatus of eukaryotes
C.
Lysosomes of eukaryotes
D.
None of these
48. Which of the following has Chinese letter arrangement?
A.
Bacillus anthracis
B.
Mycobacterium tuberculosis
C.
Clostridium tetani
D.
Corynebacterium diphtheriae
49. The other name for peptidoglycan is
A.
mucopeptide
B.
murein
C.
both (a) & (b)
D.
none of these
50. Cyanobacteria have
A.
a gram-positive cell wall
B.
a gram-negative cell wall
C.
Neither (a) nor (b)
D.
No cell wall
23
51. In which of the following, lipo-polysaccharide is a major constituent of outer
membrane of the cellwall?
A.
Gram-positive bacteria
B.
Gram-negative bacteria
C.
Fungi
D.
None of these
52. Which of the following structure(s) is /are external to cell wall?
A.
Flagella
B.
Stalks
C.
Sheath
D.
All of these
53. Which of the following may be most likely to be missing from a gram-positive
bacterium?
1.
2.
A.
Penicillin binding protein
B.
Peptidoglycan
C.
Lipopolysaccharide
D.
Phospholipid bilayer membrane
Which of the following is not the characteristic of a growth curve?
A.
Shows development of microbial population under relatively stable
environmental conditions
B.
Plotted with logarithmic numbers
C.
Graphs numbers of microbes versus time
D.
Each growth curve consists of four distinct phases
Generation time of Escherichia coli is
24
3.
4.
5.
6.
7.
A.
20 minutes
B.
20 hours
C.
20 days
D.
200 hours
The organism which obtain their energy from chemicals are designated as
A.
prototrophs
B.
chemotrophs
C.
organotrophs
D.
autotrophs
Nutrient content and biological structures are considered as
A.
implicit factor for microbial growth
B.
intrinsic factor for microbial growth
C.
processing factor
D.
none of the above
The organism which grows best above 45°C are called
A.
psychrophilic
B.
mesosphilic
C.
thermophilic
D.
any of these
Implicit factors
A.
depend on developing microflora
B.
can be synergistic
C.
both (a) and (b)
D.
none of the above
Lag phase is also known as
25
8.
9.
A.
period of initial adjustment
B.
transitional period
C.
generation time
D.
none of these
Which of the following is used to grow bacterial cultures continuously?
A.
Chemostat
B.
Coulter Counter
C.
Hemostat
D.
Petroff-Hausser chamber
A microbe, which grows at temperatures above 95° C is most likely to be
A.
an archaean
B.
a fungus
C.
a protozoan
D.
none of these
10. Some organisms can use reduced inorganic compounds as electron donors and are
termed as
A.
lithotrophs
B.
phototrophs
C.
chemotrophs
D.
photo-organotrophs
11. The total biomass of an organism will be determined by the nutrient present in the
lowest concentration relative to the organism's requirements is a statement of
A.
Liebig's law of the minimum
B.
Shelford's law of tolerance
C.
quorum sensing
D.
Heisenberg's principle of uncertainty
26
12. The growth is normally expressed as __________ in turbidimetric measurement
A.
cells per ml
B.
cfu/ml
C.
optical density
D.
mg N2 /ml
13. Which of the following organisms typically get their carbon for biosynthesis from
carbon dioxide?
A.
Glucose-fermenting bacteria (fermentation)
B.
Anaerobic, glucose-respiring bacteria (anaerobic respiration)
C.
Aerobic, glucose-respiring bacteria (aerobic respiration)
D.
Ammonia-oxidizing bacteria (chemolithotrophic bacteria)
14. An organism that expends energy to grow in a habitat with a low water activity in
order to maintain internal solute concentrations to retain water is
A.
osmotolerant
B.
acidophile
C.
aerotolerant anaerobe
D.
alkalophile
15. The straightforward method of binary fission explains how bacteria
A.
grow in nutrient agar
B.
evolve
C.
move
D.
reproduce
16. The equation used to obtain bacterial population by binary fission is
A.
N = No2n
B.
log N/No = (0.3010) n
C.
log(N/No) = nlog 2
27
D.
All of these
17. Bacteria and fungi multiply best
A.
below 16°C
B.
between 16-38°C
C.
above 38°C
D.
none of these
18. An organism has an optimal growth rate when the hydrogen ion concentration is very
high. This organism is
A.
osmotolerant
B.
acidophile
C.
neutrophile
D.
aerotolerant anaerobe
19. Which of the following procedures uses a photocell to measure absorbance of a culture
to regulate the flow of culture media?
A.
Coulter Counter
B.
Hemostat
C.
Petroff-Hausser chamber
D.
Trubidostat
20. Organisms, using organic compounds as electron donors are called
A.
lithotrophs
B.
phototrophs
C.
chemotrophs
D.
organotrophs
21. The reproduction by budding occur in
A.
Rhodopseudomonas acidophila
B.
Hyphomicrobium vulgare
C.
Bacillus subtilis
28
D.
Both (a) and (b)
22. Starvation proteins are produced by a culture during which of the following segments
of the growth curve?
A.
Lag phase
B.
Exponential phase
C.
Stationary phase
D.
Death phase
23. The cell reproduction in bacteria may occur by
A.
binary fission
B.
budding
C.
fragmentation
D.
all of these
24. During exponential growth, the growth rate is
A.
number of generations per unit time
B.
reciprocal of generation time
C.
both (a) and (b)
D.
none of these
25. A spore differs from an actively replicating bacterium in that the spore
A.
is produced during a process involving asymmetric division
B.
is able to withstand more extreme conditions than the replicating cell
C.
is metabolically inactive
D.
all of the above
26. Which of the following has more tolerance for acidic pH (lower pH)?
29
A.
Yeast and moulds
B.
Bacteria
C.
E. coli
D.
None of these
27. The ability of Vibrio fischeri to produce bioluminescence chemicals only when a certain
population density has been reached is an example of
A.
Liebig's law of the minimum
B.
Shelford's law of tolerance
C.
quorum sensing
D.
Heisenberg's principle of uncertainty
28. Antimicrobial constituents for the microbial growth in foods are
A.
intrinsic factor
B.
extrinsic factor
C.
both (a) and (b)
D.
none of these
29. The average size of cells during the exponential phase of growth is
A.
greater than the lag phase
B.
lesser than the lag phase
C.
equal to the lag phase
D.
none of these
30. A culture broth tube was very turbid at the surface but clear throughout the rest of the
tube indicating that the
A.
organism are aerobes
B.
organism should be grown in an anaerobic chamber
C.
organism cannot produce superoxide dismutase and/or catalase
30
D.
organism cannot tolerate oxygen
31. A synergistic effect is observed when
A.
one organism removes an inhibitory substance for another
B.
one organism produces a growth factor utilized by another
C.
microbial alteration of pH, aw, Eh favours the growth of another
D.
all of the above
32. Generation time is
A.
time required for the population to double
B.
time required for the initial adjustment
C.
obtained by expression t/n, where t = time interval, n = number of
generation
D.
both (a) and (c)
33. The term facultative anaerobe refers to an organism that
A.
doesn't use oxygen but tolerates it
B.
is killed by oxygen
C.
uses oxygen when present or grows without oxygen when absent
D.
requires less oxygen than is present in air
34. The microorganisms that grow best in a low-oxygen environment is called a (n)
A.
aerobe
B.
anaerobe
C.
facultative
D.
microaerophile
35. Pseudomonas pseudoflava can grow as
A.
chemo-lithotrophs
B.
chemo-organotrophs
C.
both (a) and (b)
31
D.
none of these
36. Which of the following is the suitable temperature range for mesophiles?
A.
20-30°C
B.
25-40°C
C.
>40°C
D.
None of these
37. Exponential phase of growth curve of bacteria is of limited duration because of
A.
rise in cell density
B.
accumulation of toxic metabolites
C.
exhaustion of nutrients
D.
all of these
38. A culture broth tube was very turbid at the bottom of the tube but clear at the top of the
tube indicating that the
A.
broth is sterile
B.
organism can tolerate oxygen
C.
organism cannot produce superoxide dismutase and/or catalase
D.
organism should be grown in an anaerobic chamber
39. In the exponential phase, the cells and cell mass
A.
first increases then decreases
B.
decreases
C.
are constant
D.
double at a constant rate
40. What is the primary source of food for marine life?
32
A.
Phytoplankton
B.
Zooplankton
C.
Sea weed
D.
Grass
41. Postgates assay technique is useful in determining if a cell is viable even though it is
A.
incapable of cell division
B.
too small to see
C.
an obligate aerobe
D.
a thermophile
42. What are the extrinsic factors for the microbial growth?
A.
humidity
B.
storage temperature
C.
composition of gas phase
D.
all of these
43. Quantitative measurement of bacterial growth can be carried out by measuring
A.
cell count
B.
cell mass
C.
cell activity
D.
all of these
44. Organisms such as lactobacilli that have elaborate requirements for specific nutrients
i.e. vitamins and other growth promoting substances, are generally called as
A.
fastidious hetrotrophs
B.
chemo-lithotrophs
33
C.
chemotrophs
D.
photo-organotrophs
45. The combination of low levels of NaCl, NaNO3 (sodium nitrate), and slightly acid pH
can prevent multiplication and toxin formation of
A.
Salmonella
B.
S. aureus
C.
C. botulinum
D.
all of these
46. Bacteria of genus Nitrosomonas use __________ as their electron source.
A.
ammonia
B.
H2S
C.
succinate
D.
light
47. All organisms require at least small amounts of carbondioxide, However, some can use
CO2 as their sole source of carbon. Such organisms are termed as
A.
autotrophs
B.
phototrophs
C.
chemotrophs
D.
photo-organotrophs
48. The generation time of a culture that produces two generations per hour is
A.
greater than that produces three generations per hour
B.
lesser than that produces three generations per hour
C.
equal to that produces three generations per hour
D.
none of the above
49. Autotrophic bacteria are those which
A.
make their own food
B.
form a long chain glycocalyx
C.
are highly susceptible to penicillin
34
D.
produce a blue-green pigment
50. Which of the following organisms typically get their carbon for biosynthesis from
organic compounds?
A.
Aerobic, glucose-respiring bacteria (aerobic respiration)
B.
Ammonia-oxidizing bacteria (chemolithotrophic bacteria)
C.
Photosynthetic cyanobacteria (phototrophic metabolism)
D.
None of the above
51. An organism is completely dependent on atmospheric O2 for growth. This organism is
A.
osmotolerant
B.
acidophile
C.
facultative anaerobe
D.
obligate aerobe
52. Microaerophilic bacteria are those which require
A.
21 % oxygen for growth
B.
low levels of oxygen for growth (lesser than O2 present in atmosphere)
C.
oxygen for activation of enzymes
D.
none of the above
53. The period between inoculation of bacteria in a culture medium and beginning of
multiplication is known as
A.
stationary phase
B.
log phase
C.
lag phase
D.
decline phase
54. The term aerotolerant anaerobe refers to an organism that
35
A.
doesn't use oxygen but can grow in the presence of oxygen
B.
is killed by oxygen
C.
requires less oxygen than is present in air
D.
prefers to grow without oxygen
55. The term obligate anaerobe refers to an organism that
A.
doesn't use oxygen but tolerates it
B.
is killed by oxygen
C.
uses oxygen when present or grows without oxygen when oxygen is absent
D.
prefers to grow without oxygen
The fragmentation occurs in
1.
2.
A.
Streptomyces species
B.
Nocardia species
C.
Bacillus subtilis
D.
None of these
Which of the following is/are not a gram-positive bacteria?
A.
Streptococci
B.
Pseudomonas
C.
Mycobacteria
D.
None of these
Gram-positive bacteria, responsible for food poisoning, is/are
A.
Mycoplasmas
B.
Pseudomonas
C.
Clostridia
36
D.
3.
4.
5.
6.
7.
all of these
The gram-positive bacteria lack __________ structure/component?
A.
outer membrane
B.
murein
C.
teichoic acid
D.
plasma membrane
Which of the following gram-positive bacteria causes pharyngitis (sore throat)?
A.
Neisseria
B.
Streptococcus
C.
Staphylococcus
D.
Mycobacterium
Which of the following gram-negative bacteria is/are not aerobic?
A.
Pseudomonas
B.
Neisseria
C.
Escherichia
D.
None of these
The enzyme, which hydrolyses the murein is
A.
perxoidase
B.
tannase
C.
lysozyme
D.
none of these
Bacterial spoilage is identified by which of the following morphological characteristics?
A.
Encapsulation
B.
Endospores
37
8.
9.
C.
Cell aggregation
D.
All of these
Bacteria are
A.
saprophytic
B.
symbiotic
C.
hyper parasitic
D.
all of these
Gram-negative bacteria, responsible for food poisoning, is/are
A.
Salmonella
B.
Pseudomonas
C.
Clostridia
D.
None of these
10. Coliform bacteria on fermentation of carbohydrates yields
A.
lactic acid
B.
acetic acid
C.
formic acid
D.
all of these
11. Gram-negative bacterium is/are
A.
Escherichia
B.
Clostridia
C.
Staphylococci
D.
All of these
12. Thermus thermopiles is a
38
A.
gram negative eubacteria
B.
gram positive eubacteria
C.
gram negative archebacteria
D.
gram positive archebacteria
13. Which of the following is a gram-positive bacteria?
A.
Lactobacillus
B.
Staphylococci
C.
Streptococci
D.
All of these
39
Cell and cultures
Which of the following bacteria can grow in acidic pH?
2.
3.
4.
5.
A.
Vibrio cholerae
B.
Lactobacilli
C.
Shigella
D.
Salmonella
Cell size and cell number can be measured using
A.
hemocytometer
B.
coulter counter
C.
petroff-hausser counting chamber
D.
none of these
Which of the following is used for the proper maintenance and preservation of pure
cultures?
A.
Periodic transfer to fresh media
B.
Preservation by overlaying cultures with mineral oil
C.
Preservation by lyophilization
D.
All of the above
In the process of freeze drying, a dense cell suspension is placed in small vials and is
frozen at
A.
-60 to -78°C
B.
-20 to -30°C
C.
-30 to -48°C
D.
-48 to -58°C
The solidifying agent commonly used in preparation of media is/are
A.
agar
B.
silica gel
40
6.
7.
8.
9.
C.
both (a) and (b)
D.
none of these
Which of the following chemotherapeutic agents may affect the growth
ofCampylobacter jejuni?
A.
Vacomycin
B.
Polymyxin
C.
Trimethoprim
D.
None of these
To select cholera-causing bacterium, Vibrio cholerae, the pH of the medium is
maintained at a pH of
A.
8.5
B.
8.90
C.
6.79
D.
3.5
For the selection of endospore-forming bacteria, a mixed culture can be heated at
A.
80°C for 10 minutes
B.
70°C for 10 minutes
C.
60°C for 10 minutes
D.
90°C for 10 minutes
The concentration of agar to obtain semi solid media is
A.
1.5-20%
B.
0.5% or less
C.
>10%
D.
>10%but<20%
10. Which of the following bacteria dies quickly after drying?
A.
Treponema pallidium
41
B.
Mycobacterium tuberculosis
C.
Staphylococcus aureus
D.
Pseudomonas aeruginosa
11. Mac-Conkey medium is an example of
A.
transport medium
B.
enrichment medium
C.
differential medium
D.
all of these
12. Pseudomonas aeruginosa forms a blue water soluble pigment called
A.
pyocyanin
B.
chlororaphin
C.
pyoverdin
D.
β-carotene
13. Agar is used for solidifying culture media because
A.
it does not affect by the growth of bacteria
B.
it does not add to the nutritive properties of the medium
C.
the melting and solidifying points of agar solution are not the same
D.
all of the above
14. For the selection of lactobacilli present in cheddar cheese, the pH of the medium is
maintained at
A.
6.35
B.
5.35
C.
4.35
D.
5.75
15. A disease producing species occurring in a mixed culture can often be selected on the
basis of its
42
A.
pathogenic properties
B.
special carbon source
C.
special nitrogen source
D.
none of these
16. Important example(s) of enriched medium/media is/ are
A.
Loeffler's serum slope
B.
Bordet-gengou medium
C.
Blood agar
D.
All of these
17. Cell counting can be carried out by
A.
direct microscopic count using petroffhansser counting chamber
B.
plate counting
C.
membrane filter count
D.
all of the above
18. Which of the following techniques may be performed quantitatively to determine the
number of bacteria of a particular type?
A.
Pour plate
B.
Spread plate
C.
Both (a) and (b)
D.
Streak plate technique
19. Intestinal bacteria can grow in the presence of __________ whereas nonintestinal
bacteria are usually inhibited.
A.
bile salts
43
B.
low concentration of various dyes
C.
sugars
D.
low levels of nitrogen
20. Which of the following problem makes it impossible to satisfy all of Koch's postulates?
A.
Microorganism causes serious symptoms in humans
B.
Microorganism cannot be isolated in pure culture
C.
Species of microorganism is in question
D.
Genes from the microorganism cannot be amplified by PCR
21. A medium containing crystal violet dye plus sodium deoxycholate will allow
A.
gram (-)ve intestinal bacteria to grow
B.
gram (+)ve intestinal bacteria to grow
C.
aquatic bacteria to grow
D.
none of these
22. Which of the following bacteria can grow in alkaline pH?
A.
Shigella
B.
Lactobacilli
C.
Salmonella
D.
Vibrio cholerae
23. All bacteria that inhabit the human body are
A.
heterotrophs
B.
chemolithotrophs
C.
autotrophs
D.
phototroph
24. When a substance is added to a liquid medium which inhibits the growth of unwanted
bacteria and favors the growth of wanted bacteria, it is known as
A.
differential medium
44
B.
enriched medium
C.
enrichment medium
D.
selective medium
25. Which of the following methods is most likely to be quantitative?
A.
Dilution and plating
B.
Gram staining
C.
Wet mount
D.
None of these
26. Which of the following hint(s) suggest/s that a given specimen is likely to contain
anaerobic bacteria?
A.
Gas in specimen
B.
Foul odour
C.
Presence of sulphur granules
D.
All of these
27. Viable plate count can be obtained using
A.
Spread plate method
B.
Pour plate method
C.
both (a) and (b)
D.
Hemocytometer
28. In the pour plate method, the mixed culture is diluted directly in tubes of
A.
liquid agar medium
B.
sterile liquid usually water
C.
both (a) and (b)
D.
none of these
45
29. Treponema species from human oral cavity can be selected by using
A.
pH of the medium
B.
incubation temperature
C.
cell size and motility
D.
all of these
30. When a substance is added to a solid medium which inhibits the growth of unwanted
bacteria but permits the growth of wanted bacteria, it is known as
A.
differential medium
B.
enriched medium
C.
enrichment medium
D.
selective medium
31. Peptone water and nutrient broth are
A.
selective media
B.
enriched media
C.
basal media
D.
none of these
32. Stuart's transport medium is used for transport of specimen containing
A.
Neisseria gonorrhoeae
B.
Salmonella
C.
Vibrio cholerae
D.
Shigella
33. Plate counts are often reported as
46
A.
cfu
B.
cfu/ml
C.
Both (a) and (b)
D.
thousands/ml
34. The medium which allows the growth of more than one microorganisms of interest but
with morphologically distinguishable colonies is known as
A.
selective medium
B.
enrichment medium
C.
differential medium
D.
none of these
35. Selective media facilitate growth of only one kind of organism. Saboraud medium is
used to selectively isolate
A.
coliform bacteria
B.
gram positive bacteria
C.
yeasts
D.
acid fast organisms
47
Physical and chemical agent
1.
2.
3.
4.
5.
Which of the following articles can be sterilized in an autoclave?
A.
Gloves
B.
Culture media
C.
Dressing material
D.
All of these
Which of the following disinfectants act by disrupting microbial membranes?
A.
Cationic detergents
B.
Halogens
C.
Heavy metals
D.
Aldehydes
Which of the following is best to sterilize heat labile solutions?
A.
Dry heat
B.
Autoclave
C.
Membrane filtration
D.
Pasteurization
The time required to kill 90% of the microorganisms in a sample at a specific
temperature is the
A.
decimal reduction time
B.
thermal death point
C.
F value
D.
D value
Which of the following is best used for long term storage of microbial samples when
carried out properly?
48
6.
7.
8.
9.
A.
Storage in a freezer at -10°C
B.
Storage in a freezer at ultra low temperatures (-70°C)
C.
Storage in a refrigerator on an agar slant
D.
Storage on a petri plate at room temperature
Which of the following is not a disinfectant containing a heavy metal?
A.
Silver nitrate
B.
Mercurochrome
C.
Copper sulfate
D.
Chlorine
Which is the most important surface active disinfectants?
A.
Amphoteric compounds
B.
Cationic compounds
C.
Non-ionic compounds
D.
Anionic compounds
Which disinfectant would be most effective against Staphylococcus found in a blood
spill?
A.
Phenol
B.
Cetylpyridinium chloride
C.
Hexachlorophene
D.
None of these
Which of the following substances can sterilize?
A.
Alcohol
B.
Cetylpyridinium chloride
C.
Ethylene oxide
49
D.
Chlorine
10. Milk is pasteurized in batch method by keeping it at
A.
63°C for 30 minutes
B.
72°C for 60 seconds
C.
73°C for 30 minutes
D.
72°C for 6 minutes
11. Preservation of foods by using salts and sugars works by
A.
raising pH
B.
lowering osmotic pressure
C.
creating a hypertonic environment
D.
creating a hypotonic environment
12. Which of the following items could be sterilized by dry heat sterilization?
A.
Intravenous (IV) solution
B.
Plastic IV bags
C.
Glass pipettes
D.
rubber gloves
13. Which of the following does not kill endospores?
A.
Autoclave
B.
Incineration
C.
Hot air sterilization
D.
Pasteurization
14. Which disinfectant was the most effective against Salmonella"?
50
A.
Phenol
B.
Cetylpyridinium chloride
C.
Hexachlorophene
D.
Merthiolate
15. If a canning procedure is not properly followed, which type of microbe is most likely to
grow in the canned food?
A.
Obligate Aerobe
B.
Acidophile
C.
Mesophile
D.
Obligate Anaerobe
16. Bactericidal concentration of phenol is
A.
0.25%
B.
0.5%
C.
0.75%
D.
1%
17. Which of the following is most effective for sterilizing mattresses and plastic petri
plates?
A.
Chlorine
B.
Ethylene oxide
C.
Glutaraldehyde
D.
Ultraviolet radiation
18. Which of the following skin disinfectant(s) is/are most frequently used?
A.
Isopropyl alcohol
B.
Ethyl alcohol
C.
Both (a) and (b)
51
D.
none of these
19. All of the following are sporicidal except
A.
glutaraldehyde
B.
ethylene oxide
C.
formaldehyde
D.
alcohol
20. Which of the following describes the effect of ionizing radiation on microbes?
A.
Changes the 3-dimensional structure of proteins to a 2-dimen-sional form
B.
Substantially decreases enzymatic activity, slowing microbial reproduction
C.
Induces electrons and protons to jump out of the molecules of the microbe
D.
None of the above
21. The process of making an object free from living organisms including bacterial and
fungal spores and viruses is known as
A.
pasteurization
B.
antisepsis
C.
disinfection
D.
sterilization
22. Media containing spores and thermolabile constituents are sterilized by
A.
pasteurization
B.
UV radiation
C.
dry heat
D.
tyndalization
23. A(n)____is used to prevent infection by killing or inhibiting pathogen growth on animal
tissues.
A.
bacteriostatic agent
B.
sanitizer
C.
disinfectant
52
D.
antiseptic
24. One drawback to the use of ultraviolet light as a sterilizing agent is its
A.
failure to kill bacteria
B.
failure to bacterial spores
C.
failure to kill microbes in a closed environment
D.
failure to kill microbes located in the center of an object
25. Ethylene oxide is used to destroy or kill which of the following microbes?
A.
Bacteria
B.
Spores
C.
Fungi
D.
All of these
26. Which of the following was the first widely used antiseptic and disinfectant?
A.
Chlorine
B.
Phenol
C.
Iodine
D.
Alcohol
27. If a 1:600 dilution of a test compound kills a standard population of Staphylococcus
aureus in 10 minutes but not 5 minutes while a 1:60 dilution of phenol kills the
population in the same time, what is the phenol coefficient of the test compound?
A.
1
B.
5
C.
10
D.
50
28. Microbes can be removed from a liquid solution by the process of
A.
filtration
B.
freeze-drying
C.
osmosis
D.
desiccation
29. Which of the following is bactericidal?
A.
Membrane filtration
53
B.
Ionizing radiation
C.
Freeze-drying
D.
Deep freezing
30. Which of the following process can be efficiently carried out by incineration?
A.
Sterilization of scalpel blades and needles
B.
Sterilization of all glass syringes
C.
Sterilization of points of forceps
D.
Destruction of contaminated materials
31. The organisms retained in the fluids filtered by Seitz filter is
A.
Proteus
B.
Staphylococcus
C.
Clostridium
D.
None of these
32. Which of the following material is sterilized by heating at 160°C in a hot air oven for
one hour?
A.
Swab sticks
B.
All-glass syringes
C.
Oils and jellies
D.
All of these
33. For sterilization of which material gamma rays can be used?
A.
Catheters
B.
Plastic syringes
C.
Canulas
D.
None of these
54
34. Which of the following is sterilized with the help of glutaraldehyde?
A.
Thermometers
B.
Bronchoscopes
C.
Cystoscopes
D.
All of these
35. The time in minutes at a specific temperature needed to kill a population of cells is the
A.
decimal reduction time
B.
thermal death point
C.
thermal death temperature
D.
F value
36. Which of the following is a limitation of the autoclave?
A.
It takes too long to sterilize
B.
It lacks the ability to inactivate viruses
C.
It lacks the ability to kill endospores
D.
It will destroy heat labile materials
37. Which of the following has most heat resistant spores?
A.
Clostridium histolyticum
B.
Clostridium perfringens
C.
Bacillus stearothermophilus
D.
Bacillus cereus
38. The lowest temperature that kills all microorganisms in a liquid suspension in 10
minutes is known as the
A.
decimal reduction time
55
B.
thermal death point
C.
thermal death temperature
D.
thermal death time
39. Which of the following tests is designed to simulate the natural conditions under which
the disinfectants are used in hospitals?
A.
Phenol coefficient test
B.
Minimum inhibitory concentration test
C.
Capacity test
D.
None of these
40. Steam exposure of a material at 100°C for 20 minutes for three consecutive days is
known as
A.
inspissation
B.
tyndallization
C.
autoclaving
D.
none of these
41. Which of the following material is sterilized by use of red heat?
A.
Soiled dressings
B.
Inoculating wires and loops
C.
Glass slides
D.
All-glass syringes
42. Which of the following methods will not sterilize?
A.
Aqueous glutaraldehyde for 10 hours
B.
Dry heat at 171°C for 1 to 2 hours
C.
121°C at 15 lb/in pressure for 15 to 20 minutes
D.
100°C boiling water for 30 minutes
43. Which of the following is/are vapour-phase disinfectant/s?
56
A.
Formaldehyde
B.
Ethylene oxide
C.
Both (a) and (b)
D.
None of these
44. Sweet and salty foods frequently don't require refrigeration to prevent spoilage
because they have
A.
insufficient nutrients
B.
low pH
C.
high concentration of solutes
D.
toxic alkaline chemicals
45. Iodophores are mixture of
A.
iodine and aldehydes
B.
iodine and surface active agents
C.
iodine and alcohols
D.
iodine and phenols
46. Which of the following compounds are commonly used as general antiseptics to treat
cuts and scratches?
A.
Aldehydes
B.
Ethylene oxide
C.
Halogens
D.
None of these
47. Complete destruction of the microorganisms is commonly known as
A.
disinfection
B.
sterilization
57
C.
antisepsis
D.
none of these
58