Explore topic-wise MCQs in Microbiology.

This section includes 195 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

101.

The sulphite waste liquor fermentation employs use of Candida utilis because of its ability to ferment

A. sucrose
B. pentose
C. glucose
D. maltose
Answer» C. glucose
102.

The organism commercially used for fungal fermentation to obtain citric acid is

A. A. oryzae
B. A.flavus
C. A. niger
D. S. cerevisiae
Answer» D. S. cerevisiae
103.

The organism commonly used for the production of β carotene is/ are

A. Phycomyces blakesleeanus
B. Cnoanephora cucurbitarum
C. Blakeslea trispora
D. all of these
Answer» E.
104.

Riboflavin is a by-product of __________ fermentation carried out by Clostridium spp.

A. citric acid
B. acetone butanol
C. streptomycin
D. ethanol
Answer» C. streptomycin
105.

Most productive species among the different vitamin B12 producing Pseudomonads is

A. P. denitrificans
B. P. ovalis
C. P. aureofaciens
D. none of these
Answer» B. P. ovalis
106.

Which of the following substance is employed to neutralize the lactic acid as it is produced (because lactic acid bacteria do not tolerate high concentrations of acid?

A. CaCO3
B. (NH4)2 HPO4
C. MgSO4
D. Na2SO4
Answer» B. (NH4)2 HPO4
107.

Which of the following is a cephalosporin?

A. Cephalosporin N
B. Synnematin
C. Cephalosporin C
D. All of these
Answer» E.
108.

Insulin was isolated from which of the following organs of animals?

A. small intestine
B. tongue
C. pancreas
D. stomach
Answer» D. stomach
109.

Transfer of genes between cells that are in physical contact with one another is known as transformation.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
110.

What are the characteristics of rough pneumococci strain?

A. noncapsulated and pathogenic
B. noncapsulated and nonpathogenic
C. capsulated and pathogenic
D. capsulated and nonpathogenic
Answer» C. capsulated and pathogenic
111.

What are bacteriocins?

A. proteins
B. toxins
C. plasmid
D. sex factor
Answer» B. toxins
112.

Anaerobic bacteria undergoes butyric isopropyl fermentation in carbohydrates to yield

A. glycol
B. butyric acid
C. acetic acid
D. all of these
Answer» E.
113.

The first penicillin isolated by Alexander Fleming, penicillin F is also called

A. 2-Pentenyl Penicillin
B. n-heptyl penicillin
C. phenoxymethyl penicillin
D. benzyl penicillin
Answer» B. n-heptyl penicillin
114.

Which of the following organism is utilized for the production of D-L-alanine?

A. Microbacterium ammoniaphilum
B. Brevibacterium flavum
C. Arthrobacter paraffineus
D. C. glutamicum
Answer» B. Brevibacterium flavum
115.

The maximum concentration of ethanol that is achieved by successive distillation of fermentation broth in continuous stills is

A. 60%
B. 95%
C. 70%
D. 99%
Answer» C. 70%
116.

Which of the following organism is utilized to obtain commercial L-lysine by direct method?

A. Micrococcus glutamicus
B. Mutated strain of Micrococcus glutamicus
C. Brevibacterium aminogenes
D. Mutated strain of Brevibacterium aminogenes
Answer» C. Brevibacterium aminogenes
117.

The method of distillation used to obtain alcohol greater than 95 percent is called

A. fractional distillation
B. flash evaporation
C. azeotropic distillation
D. successive distillation
Answer» D. successive distillation
118.

VP3 protein is isolated from which of the following viruses?

A. TMV
B. HIV
C. HRV
D. FMDV
Answer» E.
119.

Most biopolymers produced by micro-organisms are

A. cell wall constituents
B. nucleic acids
C. histones
D. exopolysaccharides
Answer» E.
120.

The other name of invertase enzyme is

A. sucrase
B. saccharase
C. isomerase
D. both (a) and (b)
Answer» E.
121.

Which of the following product utilises whey as its raw material?

A. lactic acid
B. acetic acid
C. glutamic acid
D. lysine
Answer» B. acetic acid
122.

The citric acid is recovered from the fermentation broth as

A. calcium citrate
B. magnesium citrate
C. zinc citrate
D. none of these
Answer» B. magnesium citrate
123.

The rapid process of microbial oxidation developed to produce acetic acid from ethanol at Schutzenbach, Germany is also known as

A. packed generator
B. trickle method
C. Orleans process
D. both (a) and (b)
Answer» E.
124.

Why high concentration of sugars are not employed in the fermentation medium?

A. Calcium lactate is not produced
B. Calcium lactate crystallizes from the medium and slows down the process of fermentation
C. High sugar concentration itself crystallizes
D. None of the above
Answer» C. High sugar concentration itself crystallizes
125.

Neomycin-B is obtained from

A. Streptomyces niveus
B. Streptomyces fradiae
C. Streptomyces spheroides
D. Streptomyces griseus
Answer» C. Streptomyces spheroides
126.

Production of L-lysine can be carried out by

A. C. glutamicum
B. B. flavum FA 1-30
C. B. flavum
D. All of these
Answer» E.
127.

Microbial rennet, which is used in cheese manufacture is produced by

A. Mucor spp
B. Aspergillus spp
C. Bacillus spp
D. Saccharomyces spp
Answer» C. Bacillus spp
128.

Glucoseoxidase, which had been commercially employed to remove glucose from egg white and whole eggs before drying is obtained by submerged aerated fermentation using

A. A. niger
B. B. subtilis
C. B. cereus
D. A.flavus
Answer» B. B. subtilis
129.

The micro-organism used for industrial production of lactic acid using corn dextrose as media is

A. Lactobacillus bulgaricus
B. Lactobacillus delbrueckii
C. Lactobacillus pentosus
D. Streptococcus lactis
Answer» C. Lactobacillus pentosus
130.

Which of the following yeast is used for the production of riboflavin?

A. Saccharomyces cerevisiae
B. Eremothecium ashbyi
C. Saccharomyces rouxii
D. Candida utilis
Answer» C. Saccharomyces rouxii
131.

What should be the minimum weight of DNA that is required for successful transformation?

A. 1000 daltons
B. 100,000 daltons
C. 300,000 daltons
D. 8 million daltons
Answer» D. 8 million daltons
132.

Penicillin G is also known as

A. hydroxy benzyl penicillin
B. phenoxy methyl penicillin
C. benzyl penicillin
D. 2-pentenyl penicillin
Answer» D. 2-pentenyl penicillin
133.

What is the shape of DNA in the male cells of E.coli?

A. linear
B. supercoiled
C. circular
D. relaxed
Answer» D. relaxed
134.

The biotin level in obtaining L-gluatmic acid by fermentation using Micrococcus glutamicus is critical because

A. too low level prevents growths, hence L-glutamic acid production
B. too high level prevents L-glutamic acid production
C. both (a) and (b)
D. none of the above
Answer» D. none of the above
135.

Amyloglucosidase is used in glucose production. It is produced by

A. Rhizopus niveus
B. Endomycopsis fibuliger
C. Sclerotina libertina
D. both (a) and (b)
Answer» E.
136.

Acridine orange is which type of mutagen?

A. base analog
B. chemical compounds
C. intercalating agents
D. transposons
Answer» D. transposons
137.

The production of acetic acid from ethanol is an

A. anaerobic process
B. aerobic process
C. a combination of both
D. none of the above
Answer» C. a combination of both
138.

Which of the following mutations result in frameshift mutation?

A. missense mutation
B. transition
C. transversion
D. insertion
Answer» E.
139.

The replacement of a purine by a pyrimidine or vice versa is known as ____________

A. tranversion
B. transition
C. base-pair substitution
D. missense mutation
Answer» B. transition
140.

In nonsense mutation, the new mRNA codon specifies the same amino acid as that from the original codon.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
141.

Which of the following mutagen causes a break in the phosphodiester backbone of the nucleic acid?

A. UV light
B. X-rays
C. Nitrous acid
D. base analogs
Answer» C. Nitrous acid
142.

Which is the functional unit of inheritance?

A. DNA
B. Chromosome
C. Gene
D. RNA
Answer» D. RNA
143.

Bacterial chromosome has the capacity to code for ____________ different proteins.

A. 900
B. 300
C. 1500
D. 3500
Answer» E.
144.

Populations of cells descending from a single cell are known as ____________

A. mutants
B. clones
C. wild-type cells
D. parent cell
Answer» C. wild-type cells
145.

Rhizopus nigricans produces which of the following products?

A. Citric acid
B. Fumaric acid
C. Gibberellic acid
D. Lactic acid
Answer» C. Gibberellic acid
146.

Invertase causes hydrolysis of ___________

A. starch
B. sucrose
C. proteins
D. pectins
Answer» C. proteins
147.

Vinegar is a fermentation derived food product containing not less than

A. 4% acetic acid
B. 15% acetic acid
C. 25% acetic acid
D. 6% acetic acid
Answer» B. 15% acetic acid
148.

Which of the following enzyme is used to join the DNA fragments together?

A. polymerases
B. exonuclease
C. endonuclease
D. ligase
Answer» E.
149.

The strain C. glutamicum can be used for the production of

A. L-ornithine
B. L-phenylalanine
C. L-glutamine
D. all of these
Answer» E.
150.

Invertase has its application in confectionaries to prevent crystallization of sugar. It is obtained from

A. A. oryzae
B. A. niger
C. S. cerevisae
D. B. subtilis
Answer» D. B. subtilis