Description : DNA fragments are sealed by (A) DNA polymerase II (B) DNA ligase (C) DNA gyrase (D) DNA topoisomerase II
Last Answer : Answer : B
Description : During DNA replication, the strands separate by (a) DNA polymerase (b) topoisomerase (c) unwindase/helicase (d) gyrase.
Last Answer : b) topoisomerase
Description : There are special proteins that help to open up DNA double helix in front of the replication fork. These proteins are (a) DNA ligase (b) DNA topoisomerase I (c) DNA gyrase (d) DNA polymerase I.
Last Answer : (c) DNA gyrase
Description : Distinctive features of gatifloxacin include the following except: A. Higher affinity for the enzyme topoisomerase IV B. Activity restricted to gram negative bacteria C. Potential to prolong QTc interval D. Employed to treat community acquired pneumonia
Last Answer : B. Activity restricted to gram negative bacteria
Description : Leishmania donovani is susceptible to certain antifungal drugs because both fungi and Leishmania: A. Utilise purine salvage pathway B. Utilise similar glycolytic mechanisms C. Have similar topoisomerase II enzyme D. Have ergosterol in their cell membranes
Last Answer : D. Have ergosterol in their cell membranes
Description : Vinca alkaloids exert antitumor activity by: A. Activating topoisomerase II to cause breaks in DNA strands B. Crosslinking DNA strands C. Inhibiting DNA mediated RNA synthesis D. Inhibiting polymerization of tubulin to form intracellular microtubules
Last Answer : D. Inhibiting polymerization of tubulin to form intracellular microtubules
Description : The most common mechanism of development of resistance to fluoroquinolones is: A. Chromosomal mutation altering affinity of target site B. Plasmid transfer C. Acquisition of drug destroying enzyme D. Acquisition of alternative metabolic pathway
Last Answer : A. Chromosomal mutation altering affinity of target site
Description : Choose the correct statement about topotecan: A. It is a DNA topoisomerase I inhibitor which causes single strand DNA breaks B. It is a cell cycle specific anticancer drug C. It is a COMT-inhibitor used in advanced parkinsonism D. Both 'A' and 'B' are correc
Last Answer : D. Both 'A' and 'B' are correct
Description : The following antibiotic(s) exert(s) a long postantibiotic effect: A. Fluoroquinolones B. β-lactams C. Aminoglycosides D. All of the above
Last Answer : D. All of the above
Description : The fluoroquinolones have improved over nalidixic acid in the following respect(s): A. They have higher antimicrobial potency B. They have extended antimicrobial spectrum C. Development of bacterial resistance against them is slow and infrequent D. All of the above
Description : The enzyme which catalyzes the unwinding of DNA helix during replication is: (1) Primase (2) Topoisomerase (3) Helicase (4) DNA polymerase
Last Answer : (3) Helicase Explanation: A type of helicase enzyme called DNA helicase catalyzes the unwinding of the DNA helix at the time of replication. It uses the energy released through hydrolysis of ATP ( ... The enzyme is needed to separate the two strands of DNA also during transcription and DNA repair.
Description : The enzyme which catalyzes the unwinding of DNA helix during replication is: (1) Primase (2) Topoisomerase (3) Helicase (4) DNApolymerase
Last Answer : C option is the answer
Description : The following fluoroquinolones have augmented activity against gram positive bacteria except: A. Lomefloxacin B. Levofloxacin C. Gatifloxacin D. Moxifloxacin
Last Answer : A. Lomefloxacin
Description : The virus directed reverse transcriptase enzyme is inhibited by: A. Amantadine B. Zidovudine C. Vidarabine D. Acyclovir
Last Answer : B. Zidovudine
Description : Ciprofloxacin inhibits (A) DNA topisomerase II (B) DNA polymerase I (C) DNA polymerase III (D) DNA gyrase
Last Answer : Answer : D
Description : A consensus sequence on DNA, called TATA box, is the site for attachment of (A) RNA-dependent DNA polymerase (B) DNA-dependent RNA polymerase (C) DNA-dependent DNA polymerase (D) DNA topoisomerase II
Description : Mammalian cells are not inhibited by low concentrations of tetracyclines that inhibit sensitive microorganisms because: A. Host cells lack active transport mechanism for tetracyclines B. Host cells actively pump out ... host cells has low affinity for tetracyclines D. Both A' and C' are correct
Last Answer : D. Both ‘A’ and ‘C’ are correct
Description : Gram negative organisms are largely insensitive to benzyl penicillin because: A. They produce large quantities of penicillinase B. They do not utilise D-alanine whose incorporation in the cell wall is inhibited ... multilayer cell wall of gram negative bacteria D. Both A' and B' are correct
Last Answer : . Benzyl penicillin is not able to penetrate deeper into the lipoprotein-peptidoglycan multilayer cell wall of gram negative bacteria
Description : Negative supercoils are introduced in DNA by (A) Helicase (B) DNA ligase (C) DNA gyrase (D) DNA polymerase III holoenzyme
Last Answer : Answer : C
Description : An eazyme produced by HIV that allows the integration of HIV DNA into the host cell's DNA is (1) Ligase (2) Integrase (3) Helicase (4) DNA gyrase
Last Answer : (2) Integrase Explanation: HIV's enzyme for inserting the DNA version of its genome into the host cell DNA is called its "integrase". HIV-1 integrase catalyzes the "cut-and-paste" action of ... to the clipped ends. It is also produced by viruses containing double-stranded DNAs for the same purpose.
Description : Viropexis takes place in the phagocytic vacuoles and is due to the action of Enzymes A- DNA gyrase B- lysosomal protease C- lysosomal lipase D- all of these
Last Answer : lysosomal protease
Description : 1. Bacteria protect themselves from viruses by fragmenting viral DNA with a. Ligase b. Endonuclease c. Exonuclease d. Gyrase
Last Answer : Ans: Endonuclease.
Description : An eazyme produced by HIV that allows the integration of HIV DNA into the host cell’s DNA is : (1) Ligase (2) Integrase (3) Helicase (4) DNA gyrase
Last Answer : Integrase
Description : From a DNA-RNA hybrid, DNA can be obtained by addition of (A) DNA B protein and ATP (B) Helicase and ATP (C) DNA topoisomerase I (D) Alkali
Description : DNA topoisomerase I of E. coli catalyses (A) Relaxation of negatively supercoiled DNA (B) Relaxation of positively supercoiled DNA (C) Conversion of negatively supercoiled DNA into positively supercoiled DNA (D) Conversion of double helix into supercoiled DNA
Last Answer : Answer : A
Description : The region of DNA known as TATA BOX is the site for binding of (A) DNA polymerase (B) DNA topoisomerase (C) DNA dependent RNA polymerase (D) Polynucleotide phosphorylase
Description : Indicate the drug(s) that is/are used to treat chronic hepatitis B: A. Human interferon α B. Lamivudine C. Amantadine D. Both 'A' and 'B'
Last Answer : D. Both 'A' and 'B'
Description : Inhibition of thromboxane synthesis by aspirin in platelets lasts for 5-7 days because: A. Aspirin persists in the body for 5-7 days B. Aspirin induced depletion of arachidonic acid lasts 5-7 ... 5-7 days D. Platelets cannot generate fresh thromboxane synthetase and their turnover time is 5-7 days
Last Answer : D. Platelets cannot generate fresh thromboxane synthetase and their turnover time is 5-7 days
Description : The Na+-Cl– symport in the early distal convoluted tubule of the kidney is inhibited by: A. Thiazides B. Metolazone C. Xipamide D. All of the above
Description : Cheese reaction' in a MAO inhibited patient manifests as: A. Precipitous fall in blood pressure and shock B. Hypertensive crisis C. Acute manic episode D. Convulsions
Last Answer : A. Precipitous fall in blood pressure and shock
Description : The following is not true of the cytochrome P450 isoenzyme CYP2D6: A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol B. It is involved in demethylation of ... for poor capacity to hydroxylate many drugs including metoprolol D. It is inhibited by quinidine
Last Answer : A. It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol
Description : The distinctive feature of the isoenzyme cyclooxygenase-2 is: A. It is not inhibited by indomethacin B. It is inducible C. It generates cytoprotective prostagladins in gastric mucosa D. It is found only in foetal tissues
Last Answer : B. It is inducible
Description : Choose the correct statement about cysteinyl leukotrienes (LT-C4/D4): A. They produce long lasting bronchoconstriction B. They produce sustained rise in blood pressure C. They are responsible ... and sequestrating neutrophils at the site of inflammation D. Their production is inhibited by rofecoxib
Last Answer : A. They produce long lasting bronchoconstriction
Description : The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that: A. They catalyse different pathways in prostanoid biosynthesis B. COX-1 is inhibited by aspirin but not COX-2 C. COX-2 is inhibited by ibuprofen but not COX-1 D. COX-1 is constitutive while COX-2 is largely
Last Answer : D. COX-1 is constitutive while COX-2 is largely
Description : The antiviral action of amantadine is exerted through: A. Interaction with the viral M2 protein B. Interaction with a virus directed thymidine kinase C. Inhibition of a viral protease enzyme D. Inhibition of viral RNA mediated DNA synthesi
Last Answer : A. Interaction with the viral M2 protein
Description : The polyene antibiotics act by: A. Inhibiting fungal cytochrome P450 enzyme B. Binding to ergosterol and creating micropores in fungal cell membrane C. Inhibiting fungal DNA synthesis D. Disorienting microtubules in fungal cells
Last Answer : B. Binding to ergosterol and creating micropores in fungal cell membrane
Description : Indicate the attribute that is common to both polymyxin B and bacitracin: A. Both are active against gram negative bacteria B. Both are too toxic for systemic use C. Both act by inhibiting bacterial cell wall synthesis D. Both a
Last Answer : B. Both are too toxic for systemic use
Description : Under physiological conditions the rate limiting enzyme in the generation of angiotensin II is: A. Renin B. Angiotensin converting enzyme C. Aminopeptidase D. Angiotensinase
Last Answer : A. Renin
Description : Which of the following would you classify as a pharmacodynamics interaction? a) ACE inhibitors with potassium-sparing diuretics cause life-threatening hyperkalaemia b) Antacids reduce the absorption ... Increased bleeding due to cimetidine and warfarin d) Probenecid increases half-life of penicillin
Last Answer : a) ACE inhibitors with potassium-sparing diuretics cause life-threatening hyperkalaemia
Description : Cancer cells may become resistant to amethopterin by (A) Developing mechanisms to destroy amethopterin (B) Amplification of dihydrofolate reducatse gene (C) Mutation in the dihydrofolate reductase ... is no longer inhibited by amethopterin (D) Developing alternate pathway of thymidylate synthesis
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : PRPP glutamyl amidotransferase, the first enzyme uniquely committed to purine synthesis is feed back inhibited by (A) AMP (B) IMP (C) XMP (D) CMP
Description : In which of the following types of enzymes an inducer is not required? (A) Inhibited enzyme (B) Cooperative enzyme (C) Allosteric enzyme (D) Constitutive enzyme
Description : An allosteric enzyme is generally inhibited by (A) Initial substrate of the pathway (B) Substrate analogues (C) Product of the reaction catalysed by allosteric enzyme (D) Product of the pathway
Description : Phosphofructokinase key enzyme in glycolysis is inhibited by (A) Citrate and ATP (B) AMP (C) ADP (D) TMP
Description : A demonstrable inducer is absent in (A) Allosteric enzyme (B) Constitutive enzyme (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141
Description : Hypnotic benzodiazepines increase the period of time spent in the following stage of sleep: A. Stage II B. Stage III C. Stage IV D. REM stage
Last Answer : A. Stage II
Description : Choose the correct statement(s) about actions of insulin: A. It favours translocation of glucose transporters from intracellular site to the plasma membrane B. It enhances transcription of lipoprotein ... vascular endothelium C. It increases production of the enzyme glucokinase D. All of the above
Description : Indicate the drug that is not effective in amoebiasis A. Ornidazole B. Mebendazole C. Satranidazole D. Secnidazole
Last Answer : B. Mebendazole
Description : Indicate the drug that can be used as an alternative to primaquine for radical cure of vivax malaria: A. Atovaquone B. Bulaquine C. Tetracycline D. Proguanil
Last Answer : B. Bulaquine