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.

1.

The medium required for glutamic acid mainly consist of

A. glucose
B. molasses
C. sucrose
D. lactose
Answer» B. molasses
2.

Which of the following species is used for vitamin B12 production by fermentation process?

A. Streptomyces griseus
B. Streptomyces olivaceus
C. Bacillus megaterium
D. All of these
Answer» E.
3.

How much time is required to inject a copy of the whole Hfr E.coli genome?

A. 24 hrs
B. 30 mins
C. 100 mins
D. 48 hrs
Answer» D. 48 hrs
4.

The viral DNA may be incorporated into the phage head during phage assembly.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
5.

"Vinegar mother" in Orleans process is

A. inoculum of acetobacter bacteria used
B. considerable slime and film growth of Acetobacter bacteria on the surface of the alcoholic broth
C. cellulosic strands produced by Acetobacter bacteria to hold cells together
D. none of the above
Answer» C. cellulosic strands produced by Acetobacter bacteria to hold cells together
6.

The submerged fermentation of vinegar utilizes special fermentor designs known as

A. acetator
B. cavitator
C. packed vinegar generator
D. both (a) and (b)
Answer» E.
7.

Which of the following is not a principal media for industrial alcohol production by fermentation?

A. Black strap molasses
B. Sulphite waste liquor
C. Wood waste
D. Glucose
Answer» E.
8.

Which of the following organism produces enzyme taka diastase?

A. A. oryzae
B. B. subtilis
C. A. niger
D. S. cerevisiae
Answer» B. B. subtilis
9.

The organism B. brevis can be used commercially for the production of

A. gramicidin A
B. tyrothricin(bacitracin tyrocidin complex)
C. tyrocidin
D. all of the above
Answer» E.
10.

The organisum used for production of streptomycin is

A. Streptomyces rimosus
B. Streptomyces griseus
C. Streptomyces aureofaciens
D. Streptomyces erythreus
Answer» C. Streptomyces aureofaciens
11.

β-carotene is also known as

A. vitamin A
B. provitamin A
C. vitamin C
D. vitamin D
Answer» C. vitamin C
12.

The penicillin F which was produced at first, required the mold

A. Penicillium chrysogenum
B. Pencillium notatum
C. Pencillium chrysogenum Q-176
D. none of the above
Answer» C. Pencillium chrysogenum Q-176
13.

The 95% ethanol is equivalent to

A. 190 proof
B. 110 proof
C. 170 proof
D. 120 proof
Answer» B. 110 proof
14.

The organism used to produce L-glutamic acid is

A. Micrococcus glutamicus
B. Brevibacterium aminogenes
C. Arthrobacter globiformis
D. all of these
Answer» E.
15.

The DNA uptake process does not require any energy.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
16.

The Hfr chromosome is transferred to the F— cell in a _____________ fashion.

A. circular
B. coiled
C. dimer
D. linear
Answer» E.
17.

Malt used to ferment beer is prepared by

A. roasting barley
B. washing the barley with water and drying it in air
C. soaking barley in water followed by germination and drying
D. treating barley with bovine amylase followed by roasting
Answer» D. treating barley with bovine amylase followed by roasting
18.

Bacteriophages inject their nucleic acid into the bacterium.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
19.

Which of the following micro organism utilizes lactose as a carbon source in production of lactic acid from whey media?

A. Lactobacillus bulgaricus
B. Lactobacillus delbrueckii
C. Lactobacillus pentosus
D. Leuconostoc mesenteroides
Answer» B. Lactobacillus delbrueckii
20.

When viral genome can become integrated into the bacterial genome they are known as ____________

A. temperate phage
B. prophage
C. bacteriophage
D. episome
Answer» C. bacteriophage
21.

The early assay employed for measuring penicillin activity were based upon the quantity required to prevent growth of S. aureus over

A. 20 mm diameter zone using the cylinder plate method of assay
B. 24 mm diameter zone using the cylinder plate method of assay
C. 200 mm diameter zone using the cylinder plate method of assay
D. None of the above
Answer» C. 200 mm diameter zone using the cylinder plate method of assay
22.

The transfer of naked DNA from one cell to another is referred to as _______________

A. Transduction
B. Lysogeny
C. Transformation
D. Conjugation
Answer» D. Conjugation
23.

The Candida species require fermentation equipment lined with plastic because they are extremely sensitive to

A. traces of cobalt
B. traces of nickel
C. traces of iron
D. none of these
Answer» D. none of these
24.

Cephalosporin an antibiotic closely related to penicillin in structure and antibiotic activity are produced by species of

A. Cephalosporium
B. Cephalospodium
C. Pseudomonas
D. Bacillus
Answer» C. Pseudomonas
25.

Who was the first scientist to observe the antibiotic and therapeutic properties of penicillin?

A. Louis Pasteur
B. Alexander Fleming
C. S. C. Prescott
D. E. P. Abraham
Answer» C. S. C. Prescott
26.

In Corynebacterium glutamicum, tryptophan biosynthesis is regulated by the activity of

A. DAHP synthetase
B. Anthranilate synthase
C. Both (a) and (b)
D. Phosphoenol pyruvate
Answer» D. Phosphoenol pyruvate
27.

The organism which utilizes the pentose of sulphite waste liquor for lactic acid production is

A. Streptococcus lactis
B. Lactobacillus bulgaricus
C. Lactobacillus casei
D. Lactobacillus pentosus
Answer» E.
28.

The sugar concentration of molasses used in fermentation should be

A. 10-18%
B. 20-30%
C. 4-5%
D. 30-38%
Answer» B. 20-30%
29.

The aerated submerged bacterial fermentation to produce vitamin B12 employs strains of

A. Propionibacterium
B. Pseudomonas
C. Acetobacter
D. both (a) and (b)
Answer» E.
30.

Rickes et al. recovered active crystalline vitamin B12 from the culture of

A. Streptomyces griseus
B. Bacillus megaterium
C. Streptomyces olivaceus
D. Streptomyces lactis
Answer» B. Bacillus megaterium
31.

Which of the following cephalosporin is more active than penicillin against various species of Salmonella?

A. Cephalosporin N
B. Cephalosporin C
C. Synnematin
D. Both (a) and (c)
Answer» E.
32.

The enzyme which converts optically active isomers of lactic acid to the optically inactive racemic mixture is

A. isomerase
B. racemase
C. dehydrogenase
D. invertase
Answer» C. dehydrogenase
33.

Which of the following things was identified as the transforming principle?

A. DNA
B. RNA
C. Proteins
D. Carbohydrates
Answer» B. RNA
34.

In Griffith’s experiment which of the following strains of pneumococci was isolated from dead mice?

A. live rough cells
B. dead rough cells
C. live smooth cells
D. dead smooth cells
Answer» D. dead smooth cells
35.

The major organism used in the microbial production of citric acid is

A. Penicillin notatum
B. Rhizopus nigrificins
C. Aspergillus niger
D. Lactobacillis delbrueckii
Answer» D. Lactobacillis delbrueckii
36.

A major organism used in commercial bioleaching for copper recovery is

A. Desulfovibrio desulfuricans
B. Pseudomonas aeruginosa
C. Aspergillus niger
D. Thiobacillus ferrooxidans
Answer» E.
37.

Which of the following are commercially used for bacterial amylases production?

A. Bacillus subtilis
B. Bacillus diastaticus
C. Clostridium acetobutylicum
D. Both (a) and (b)
Answer» E.
38.

Penicillin was first produced commercially using

A. stationary mat culture
B. deep tank aerated fermentations
C. continuous fermentation
D. none of the above
Answer» B. deep tank aerated fermentations
39.

The first commercial fermention carried out to obtain L-lysine is known as

A. dual fermentation
B. indirect fermentation
C. direct fermentation
D. both (a) and (b)
Answer» E.
40.

The medium utilized for fungal citric acid production should be deficient in

A. phosphate
B. manganese
C. iron
D. all of these
Answer» E.
41.

Bacillus thuringiensis is useful as a bacterial

A. source of antibiotics
B. producer of vitamins
C. herbicide
D. pesticide
Answer» E.
42.

Which of the following can be used as a measure to construct a linkage map of the Hfr chromosome?

A. frequency of recombination
B. time of entry
C. locus of mutation
D. transfer of F factor
Answer» C. locus of mutation
43.

The present day high yielding penicillin are obtained from

A. Penicillium chrysogenum (NRRL, 1951)
B. Penicillium chrysogenum (Q-176)
C. Penicillium chrysogenum (Q-179)
D. none of the above
Answer» C. Penicillium chrysogenum (Q-179)
44.

Which of the following is known for greater stability of the riboflavin producing capacity?

A. Eremothecium ashbyii
B. Ashbya gossypii
C. Candida flareri
D. None of these
Answer» C. Candida flareri
45.

The beet molasses is pretreated with __________ to reduce great quantity of trace metals.

A. ferrocyanide or ferricyanide
B. ethylenediamine tetrachloro acetic acid
C. hydrochloric acid
D. sulphuric acid
Answer» B. ethylenediamine tetrachloro acetic acid
46.

The cell in which the F factor carries along with it some chromosomal genes are known as ____________

A. F+ cell
B. F— cell
C. F’ cell
D. F’’’ cell
Answer» D. F’’’ cell
47.

How many percent of thr+ transducing phages also carry leu+?

A. 10%
B. 5%
C. 3%
D. 15%
Answer» D. 15%
48.

Which of the following is true for an Hfr X F— cross?

A. frequency of recombination high,transfer of F factor low
B. frequency of recombination high,transfer of F factor high
C. frequency of recombination low,transfer of F factor high
D. frequency of recombination low,transfer of F factor low
Answer» B. frequency of recombination high,transfer of F factor high
49.

The recovery of vitamin from fermentation broth is carried out prior to

A. acidification
B. alcohol treatment
C. autolysis
D. none of these
Answer» D. none of these
50.

Genetic recombination occurs between homologous chromosomes.

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