MCQOPTIONS
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MCQOPTIONS
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.
| 51. |
The precursor of Penicillin G is |
| A. | phenoxy acetic acid |
| B. | phenyl acetic acid |
| C. | hydroxy phenyl acetic acid |
| D. | none of these |
| Answer» C. hydroxy phenyl acetic acid | |
| 52. |
B. flavum strain can be used for the production of |
| A. | L-Threonine |
| B. | L-Proline |
| C. | L-Isoleucine and L-Histidine |
| D. | All of the above |
| Answer» E. | |
| 53. |
An "International Unit" of penicillin activity established in 1944 is amount of penicillin equivalent to |
| A. | 0.6 micrograms of crystalline penicillin G of about 98% purity |
| B. | 0.6 micrograms of crystalline penicillin F of about 98% purity |
| C. | 0.8 micrograms of crystalline penicillin G of about 98% purity |
| D. | 0.8 micrograms of crystalline penicillin G of about 90% purity |
| Answer» B. 0.6 micrograms of crystalline penicillin F of about 98% purity | |
| 54. |
Which of the enzymes are used to cut the recipient DNA? |
| A. | endonuclease |
| B. | exonuclease |
| C. | ligases |
| D. | polymerase |
| Answer» B. exonuclease | |
| 55. |
The man who first discovered the chemical that causes souring of milk was |
| A. | Pasteur |
| B. | Scheele |
| C. | Watson |
| D. | Ronald Ross |
| Answer» C. Watson | |
| 56. |
Alcohol production from starch and raw sugar utilizes selected strains of |
| A. | Saccharomyces cerevisiae |
| B. | Candida pseudotropicalis |
| C. | Candida utilis |
| D. | none of these |
| Answer» B. Candida pseudotropicalis | |
| 57. |
Species of the genus Streptomyces are known for |
| A. | the production of antibiotics |
| B. | the production of beer |
| C. | the production of cheese |
| D. | nitrification |
| Answer» B. the production of beer | |
| 58. |
The first demonstration of recombination in bacteria was achieved by _______________ |
| A. | Lederberg and Tatum |
| B. | Luria and Delbruck |
| C. | Joshua and Lederberg |
| D. | Luria and Tatum |
| Answer» B. Luria and Delbruck | |
| 59. |
Microbially produced streptokinase is used to |
| A. | remove spots from laundry products |
| B. | dissolve clots for patients with coronary blockages |
| C. | clarify fruit juice |
| D. | breakdown starch molecules into smaller sugars |
| Answer» C. clarify fruit juice | |
| 60. |
Which of the following Ascomycetes are used for riboflavin production? |
| A. | Eremnothecium ashbyii |
| B. | Ashbya gossypii |
| C. | Candida guilliermondia |
| D. | Both (a) and (b) |
| Answer» E. | |
| 61. |
The immediate precursor for glumatic acid production by Corynebacterium glutamicum is |
| A. | lysine |
| B. | oxoacetate |
| C. | citrate |
| D. | 2-oxo-glutarate |
| Answer» E. | |
| 62. |
What is the frequency of defective phage particles in progeny phage produced? |
| A. | 100 |
| B. | 10^-1 |
| C. | 10^-5 |
| D. | 1000 |
| Answer» D. 1000 | |
| 63. |
The species of Acetobacter which produces cellulosic strands to hold the cells in lime layer is |
| A. | Acetobacter curvum |
| B. | Accetobacter orleanense |
| C. | Acetobacter xylinum |
| D. | Acetobacter schuetzenbachii |
| Answer» D. Acetobacter schuetzenbachii | |
| 64. |
Protease, which is used for flavouring of sake and haze removal in sake is produced by |
| A. | A. oryzae |
| B. | A. flavus |
| C. | B. cereus |
| D. | A. niger |
| Answer» B. A. flavus | |
| 65. |
Which of the following microorganism produces only L(+) - lactic acid without further racemization ? |
| A. | Leuconostoc mesenteroides |
| B. | Lactobacillus delbrueckii |
| C. | Rhizopus oryzae |
| D. | Lactobacillus bulgaricus |
| Answer» D. Lactobacillus bulgaricus | |
| 66. |
Which of the following is a heterofermentative micro-organism? |
| A. | Leuconostoc mesenteroides |
| B. | Lactobacillus delbrueckii |
| C. | Lactobacillus bulgaricus |
| D. | Lactobacillus pentose |
| Answer» C. Lactobacillus bulgaricus | |
| 67. |
Fragments transferred by a bacteriophage contains how many genes? |
| A. | 20 |
| B. | 50 |
| C. | 1 |
| D. | 100 |
| Answer» E. | |
| 68. |
Chlorotetracycline a broad spectrum antibiotic is produced by |
| A. | Streptomyces aureofaciens |
| B. | Streptomyces rimosus |
| C. | Streptomyces venezuelae |
| D. | Streptomyces erythreus |
| Answer» B. Streptomyces rimosus | |
| 69. |
Bacterial recombination causes transformation of the recipient cell to _______________ |
| A. | donor cell |
| B. | merozygote |
| C. | zygote |
| D. | recipient cell |
| Answer» C. zygote | |
| 70. |
How many DNA molecules are transferred after each transformation? |
| A. | 2 |
| B. | 1 |
| C. | 50 |
| D. | infinite |
| Answer» C. 50 | |
| 71. |
When the phage transduces only those bacterial genes adjacent to the prophage in the bacterial chromosome then it is known as? |
| A. | generalized transduction |
| B. | specialized transduction |
| C. | restricted transduction |
| D. | conjugation |
| Answer» D. conjugation | |
| 72. |
How much time is taken by the new DNA to make whole phage particles? |
| A. | 24 hours |
| B. | 60 mins |
| C. | 2 mins |
| D. | 10-20 mins |
| Answer» E. | |
| 73. |
Which of the following when used in proper concentration stimulates the Ascomycetes fermentation of vitamin B12 and can be used to counteract toxicity of iron in Candida species? |
| A. | Co |
| B. | Ni |
| C. | Zn |
| D. | Ca |
| Answer» B. Ni | |
| 74. |
Naringinase, an enzyme commonly used for removal of bitter taste from citrus juice is obtained from |
| A. | A. niger |
| B. | A.flavus |
| C. | A. oryzae |
| D. | S. cerevisiae |
| Answer» B. A.flavus | |
| 75. |
Which species from the followings is resistant to methyl tryptophan? |
| A. | Candida utilis |
| B. | E. coli |
| C. | B. subtilis |
| D. | Hansenula anomala |
| Answer» D. Hansenula anomala | |
| 76. |
The precursor used for production of vitamin B12 by Streptomyces olivaceus is |
| A. | cobalt chloride |
| B. | cobalt sulphate |
| C. | calcium chloride |
| D. | calcium sulphate |
| Answer» B. cobalt sulphate | |
| 77. |
Cycloserine may be isolated from the cultures of |
| A. | S. orchidaceus |
| B. | S. lavendulae |
| C. | S. garyphalus |
| D. | All of these |
| Answer» E. | |
| 78. |
Which of the following are true for the heterofermentative microorganism producing lactic acid? |
| A. | Only trace amounts of end products other than lactic acid |
| B. | Some lactic acid with carbon dioxide, ethyl alcohol, acetic acid and trace amount of few other products |
| C. | They are used for commercial lactic acid production |
| D. | None of the above |
| Answer» C. They are used for commercial lactic acid production | |
| 79. |
Which of the following is not an industrial product made by the fungus Aspergillus niger? |
| A. | Galactosidase |
| B. | Citric acid |
| C. | Gluconic acid |
| D. | Lysine |
| Answer» E. | |
| 80. |
A major organic acid produced by a microbial process used in foods is |
| A. | sulfuric acid |
| B. | citric acid |
| C. | oxalic acid |
| D. | uric acid |
| Answer» C. oxalic acid | |
| 81. |
Which of the following role is performed by a bacteriophage in transduction? |
| A. | vector |
| B. | donor |
| C. | recipient |
| D. | episome |
| Answer» B. donor | |
| 82. |
Which among the following species have not been transformed? |
| A. | Bacillus |
| B. | Neisseria |
| C. | Rhizobium |
| D. | Aspergillus |
| Answer» E. | |
| 83. |
The commonly used media for submerged bacterial fermentation at commercial scale is |
| A. | beet molasses |
| B. | liver extract |
| C. | germinated seed |
| D. | none of these |
| Answer» B. liver extract | |
| 84. |
What is the correct order when coliphage P1 is grown in a thr+ leu+ aziR host is used to infect a thr- leu- azi- recipient bacterial cell? |
| A. | thr+ leu+ aziR |
| B. | thr– leu+ aziR |
| C. | thr+ leu– aziR |
| D. | thr– leu– aziR |
| Answer» B. thr– leu+ aziR | |
| 85. |
Which among the following are not used as raw materials for alcohol production? |
| A. | corn |
| B. | molasses |
| C. | whey |
| D. | grapes |
| Answer» D. grapes | |
| 86. |
Which of the following raw materials are important for the production of glutamic acid? |
| A. | glycerol |
| B. | corn-steep liquor |
| C. | tryptone |
| D. | biotin |
| Answer» E. | |
| 87. |
Which of the following product is used for the treatment of blood clots? |
| A. | insulin |
| B. | interferon |
| C. | urokinase |
| D. | somatostatin |
| Answer» D. somatostatin | |
| 88. |
Which of the following microorganism produces dextran? |
| A. | Bacillus polymyxa |
| B. | Bacillus thuringiensis |
| C. | Leuconostoc mesenteroides |
| D. | Streptomyces olivaceus |
| Answer» D. Streptomyces olivaceus | |
| 89. |
Which of the following carbohydrates are mainly present in whey? |
| A. | glucose |
| B. | lactose |
| C. | fructose |
| D. | sucrose |
| Answer» C. fructose | |
| 90. |
Which of the following product is used as a food condiment? |
| A. | Baker’s yeast |
| B. | Ethanol |
| C. | Wine |
| D. | Soy sauce |
| Answer» E. | |
| 91. |
Transfection involves the introduction of plasmid hybrid DNA into the host cell. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 92. |
The organism used for alcohol fermentation should have a high tolerance for alcohol. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 93. |
Which of the following instrument is used for recovery of yeast cells? |
| A. | fermenter |
| B. | centrifuge |
| C. | filter press |
| D. | mash storage |
| Answer» D. mash storage | |
| 94. |
Microbial fermentation produces D optical isomers of the amino acids. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 95. |
Which of the following product is used for treatment of pernicious anemia? |
| A. | Insulin |
| B. | Streptokinase-streptodornase |
| C. | Cobalamin |
| D. | Sorbose |
| Answer» D. Sorbose | |
| 96. |
Diaminopimelic acid (DAP) is produced by which of the following microorganism? |
| A. | E.coli |
| B. | Enterobacter aerogenes |
| C. | Bacillus subtilis |
| D. | Streptococcus equisimilis |
| Answer» B. Enterobacter aerogenes | |
| 97. |
Lactobacillus bulgaricus is a homofermentative organism. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 98. |
What is the mutation rate for E.coli per bacterium per cell division? |
| A. | 5.8 x 10^-6 |
| B. | 5.8 x 10^-9 |
| C. | 5.8 x 10^-8 |
| D. | 5.8 x 10^-7 |
| Answer» D. 5.8 x 10^-7 | |
| 99. |
Photoreactivation can cause repair of DNA damaged by which of the following mutagens? |
| A. | UV rays |
| B. | X-rays |
| C. | Nitrous acid |
| D. | Base analogs |
| Answer» B. X-rays | |
| 100. |
Erythromycin a broad spectrum antibiotic is obtained with the help of |
| A. | Streptomyces rimosus |
| B. | Streptomyces venezuelae |
| C. | Streptomyces erythreus |
| D. | Streptomyces halstedii |
| Answer» D. Streptomyces halstedii | |