MCQOPTIONS
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MCQOPTIONS
This section includes 151 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Streptomyces orientalis produces which of the following antibiotics? |
| A. | Cephalosporins |
| B. | Cycloserine |
| C. | Bacitracin |
| D. | Vancomycin |
| Answer» E. | |
| 102. |
Which of the following interferes with regeneration of the monophosphate form of bactoprenol from the pyrophosphate form? |
| A. | Vancomycin |
| B. | Ampicillin |
| C. | Bacitracin |
| D. | Cephalosporins |
| Answer» D. Cephalosporins | |
| 103. |
Temperature required for 'sterilization' with dry heat is |
| A. | 180°C |
| B. | 183°C |
| C. | 189°C |
| D. | 190°C |
| Answer» B. 183°C | |
| 104. |
Inhibition of protein synthesis by 'Chloramphenicol' is result of its bonding with |
| A. | 30S ribosomal unit |
| B. | 50S ribosomal unit |
| C. | 60S ribosomal unit |
| D. | 70S ribosomal unit |
| Answer» C. 60S ribosomal unit | |
| 105. |
when a standard first line drug had failed to recover a particular condition, a new drug introduced, is classified as |
| A. | First line drugs |
| B. | Drug therapy |
| C. | Chemotherapy |
| D. | Second line drug |
| Answer» E. | |
| 106. |
The penicillin resistant to β-lactamases is |
| A. | carbenicillin |
| B. | closacillin |
| C. | penicillin-G |
| D. | ampicillin |
| Answer» C. penicillin-G | |
| 107. |
Tyrocidines are more effective against ___________________ |
| A. | Gram-positive organisms |
| B. | Gram-negative organisms |
| C. | Mycoplasmas |
| D. | Spirochetes |
| Answer» B. Gram-negative organisms | |
| 108. |
For prevention of N. meningitidis and Haemophilus influenza, causes meningitis, drug used to recover is |
| A. | Rifampin |
| B. | Isonazids |
| C. | Pentamidin |
| D. | Penicillin |
| Answer» B. Isonazids | |
| 109. |
Bacterial cells susceptible to penicillium can be protected from destruction if the medium in which they are exposed is of |
| A. | high osmotic pressure |
| B. | low osmotic pressure |
| C. | moderate osmotic pressure |
| D. | high surface tension |
| Answer» B. low osmotic pressure | |
| 110. |
Chelate forming peptide antibiotic are/is |
| A. | bleomycins |
| B. | sideromycins |
| C. | both (a) and (b) |
| D. | vancomycin |
| Answer» D. vancomycin | |
| 111. |
'B' and 'T' cells are two types of white blood cells that mediate the |
| A. | Passive immunity |
| B. | Active immunity |
| C. | Resistance |
| D. | Immunity |
| Answer» B. Active immunity | |
| 112. |
Quinolones are |
| A. | antimetabolites |
| B. | penicillin derivatives |
| C. | bacteriostatic |
| D. | broad-spectrum |
| Answer» E. | |
| 113. |
The scientist who first discovered the substance penicillin was |
| A. | Joseph Lister |
| B. | Alexander Fleming |
| C. | Paul Ehrlich |
| D. | none of these |
| Answer» C. Paul Ehrlich | |
| 114. |
Which of the following is the most accurate method for microbial assay of antibiotics? |
| A. | Physical assay |
| B. | Chemical assay |
| C. | Biological assay |
| D. | Chemical and biological assay |
| Answer» C. Biological assay | |
| 115. |
The third generation cephalosporin agents is |
| A. | cefotaxime |
| B. | cefoxitin |
| C. | cephalothin |
| D. | cephalexin |
| Answer» B. cefoxitin | |
| 116. |
The antibiotic penicillin was discovered by which of the following researchers? |
| A. | Emmerich and Low |
| B. | Gratia and Dath |
| C. | Alexander Flemming |
| D. | Vuillemin |
| Answer» D. Vuillemin | |
| 117. |
Zone of inhibition is observed in tube-dilution method. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 118. |
'Topoisomerases' is also known as |
| A. | Amylase |
| B. | Gyrase |
| C. | Ligase |
| D. | Polymerase |
| Answer» C. Ligase | |
| 119. |
Pigs respond dramatically to the addition of which of the following antibiotics to their diet? |
| A. | aureomycin |
| B. | terramycin |
| C. | penicillin |
| D. | oxytetracycline |
| Answer» E. | |
| 120. |
Which of the following group is not the carbohydrate containing antibiotic? |
| A. | Streptomycin & Streptothricin |
| B. | Vancomycin & Moenomycin |
| C. | Everninomycin & Nogirimycin |
| D. | Erythromycin & candicidin |
| Answer» E. | |
| 121. |
Which of the following protein synthesis mechanisms may be affected by particular drugs? |
| A. | Peptide bond formation |
| B. | mRNA translocation |
| C. | Aminoacyl-tRNA binding |
| D. | All of these |
| Answer» E. | |
| 122. |
When using alcohol as an antiseptic, which concentration is considered most effective? |
| A. | 95% |
| B. | 50% |
| C. | 70% |
| D. | 25% |
| Answer» D. 25% | |
| 123. |
Which of the following is used only in life-threatening situations when no other drug is adequate? |
| A. | Penicillin |
| B. | Tetracycline |
| C. | Chloramphenicol |
| D. | Streptomycin |
| Answer» D. Streptomycin | |
| 124. |
Who developed the concept of specific toxicity? |
| A. | Pasteur |
| B. | Fleming |
| C. | Watson |
| D. | Ehrlich |
| Answer» E. | |
| 125. |
Fluoroquinolones are antibiotics which inhibit |
| A. | DNA polymerase |
| B. | RNA polymerase |
| C. | DNA gyrase |
| D. | Cross-linking of peptidoglycan |
| Answer» D. Cross-linking of peptidoglycan | |
| 126. |
Which of the following drugs involves modification of the drug by enzymatic modification or degradation of its active element to alter its/their resistance? |
| A. | Pencillins |
| B. | Choloramphenicol |
| C. | Aminoglyosides |
| D. | All of these |
| Answer» E. | |
| 127. |
Structurally all penicillins have only beta-lactam present in them. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 128. |
The crystalline sodium or potassium salts are slightly soluble in ___________ |
| A. | ether |
| B. | dioxane |
| C. | water |
| D. | chloroform |
| Answer» E. | |
| 129. |
Which of the following does not affect the activity of penicillin? |
| A. | bile |
| B. | hydrochloric acid |
| C. | cysteine |
| D. | sodium hydroxide |
| Answer» B. hydrochloric acid | |
| 130. |
Benzylpenicillin is the chemical name for which of the following penicillin? |
| A. | Penicillin G |
| B. | Penicillin V |
| C. | Penicillin F |
| D. | Phenethicilin |
| Answer» B. Penicillin V | |
| 131. |
Chemotherapeutic agents must |
| A. | prevent/destroy the activity of a parasite |
| B. | leave unaltered the host's natural defense mechanisms |
| C. | be able to come in contact with the parasite by penetrating the cells |
| D. | all of the above |
| Answer» E. | |
| 132. |
Ampicillin is a bactericidal antibiotic. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 133. |
Which of the following methods would be most appropriate for sterilizing an antibiotic solution? |
| A. | Dry heat sterilization |
| B. | Microfiltration |
| C. | Autoclaving |
| D. | Desiccation |
| Answer» C. Autoclaving | |
| 134. |
By which of the following means antifungal chemotherapeutic agents may affect fungi? |
| A. | Interfere with nuclear division by preventing the aggregation of microtubules needed for mitosis |
| B. | Interfere with normal nucleic acid synthesis |
| C. | Interfere with ergosterol biosynthesis and thus alter the structure of the cytoplasmic membrane as well as the function of several membrane-bound enzymes like those involved in nutrient transport and chitin synthesis |
| D. | all of these |
| Answer» E. | |
| 135. |
Interference mechanism of ciprofloxacin and norfloxacin is due to their action on |
| A. | cell wall synthesis |
| B. | cell membrane function |
| C. | DNA function |
| D. | protein synthesis |
| Answer» D. protein synthesis | |
| 136. |
Novobiocin can be used against |
| A. | gram +ve Staphylococci |
| B. | gram -ve Meningococci & Gonococci |
| C. | Haemophilus |
| D. | all of these |
| Answer» E. | |
| 137. |
Which antibiotic has a beta-lactam ring? |
| A. | Cephalosporin |
| B. | Penicillin |
| C. | Tetracycline |
| D. | Streptomycin |
| Answer» C. Tetracycline | |
| 138. |
Which of the antibiotic is not used as a food preservative ? |
| A. | Pimaricin |
| B. | Nisin |
| C. | Tylosin |
| D. | β-lactam antibiotic |
| Answer» E. | |
| 139. |
Cycloserine inhibits |
| A. | alanine racemase |
| B. | D-alanyl - D-alanine synthetase |
| C. | Both (a) and (b) |
| D. | amidase |
| Answer» D. amidase | |
| 140. |
Which of the following is a drug that interferes with the process of DNA production in the virus that causes genital herpes? |
| A. | Erythromycin |
| B. | Vancomycin |
| C. | Amantadine |
| D. | Acyclovir |
| Answer» E. | |
| 141. |
The most selective antibiotics are those that interfere with the synthesis of |
| A. | bacterial DNA |
| B. | bacterial RNA |
| C. | bacterial cell walls |
| D. | bacterial plasma membrane |
| Answer» D. bacterial plasma membrane | |
| 142. |
Amantadine is very effective against influenza A virus. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 143. |
Which of the following has its antiviral action attributed to interference of protein synthesis? |
| A. | Amantadine |
| B. | Interferons |
| C. | Acycloguanosine |
| D. | 5’-iododeoxyuridine |
| Answer» C. Acycloguanosine | |
| 144. |
Acycloguanosine is a nucleoside analog which is active against ___________________ |
| A. | Influenza A virus |
| B. | HIV virus |
| C. | Herpes virus |
| D. | Influenza B virus |
| Answer» D. Influenza B virus | |
| 145. |
Which of the following is effective in the control of tuberculosis in humans? |
| A. | Nitrofurans |
| B. | Nalidixic Acid |
| C. | Sibromycin |
| D. | Isoniazid |
| Answer» E. | |
| 146. |
Anthramycin is which of the following type of antibiotic? |
| A. | Antiviral |
| B. | Antitumor |
| C. | Antifungal |
| D. | Antibacterial |
| Answer» C. Antifungal | |
| 147. |
Sulfanilamide was synthesized by which of the following research scientists? |
| A. | Eisenberg |
| B. | Gelmo |
| C. | Ehrlich |
| D. | Domagk |
| Answer» C. Ehrlich | |
| 148. |
Which of the following is not a characteristic of a chemotherapeutic agent? |
| A. | low toxicity for host cells |
| B. | high toxicity for the parasites |
| C. | less penetrating power |
| D. | does not affect the host’s natural defense mechanism |
| Answer» D. does not affect the host’s natural defense mechanism | |
| 149. |
Phenol is considered as a chemotherapeutic agent. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 150. |
Which was the first disease for which a chemotherapeutic agent was used? |
| A. | Syphilis |
| B. | Malaria |
| C. | Small pox |
| D. | AIDS |
| Answer» B. Malaria | |