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
Last Answer : Answer : B
Description : All of the following statements about bacterial promoters are true except (A) They are smaller than eukaryotic promoters (B) They have two consensus sequences upstream from the transcription star site (C) ... is the site for attachment of RNA polymerase (D) TATA box has a high melting temperature
Last Answer : Answer : D
Description : During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called? (a) AAAT box (b) TATA box (c) GGTT box (d) CAAT box
Last Answer : (c) GGTT box
Last Answer : (b) TATA box
Description : The binding of prokaryotic DNA dependent RNA polymerase to promoter sits of genes is inhibited by the antibiotic: (A) Streptomycin (B) Rifamcin (C) Aueromycin (D) Puromycin
Description : The binding of prokaryotic DNA dependent RNA polymerase to promoter sites of genes is inhibited by the antibiotic: (A) Puromycin (B) Rifamycin (C) Terramycin (D) Streptomycin
Description : The correct statement concerning RNA and DNA polymerases is (A) RNA polymerase use nucleoside diphosphates (B) RNA polymerase require primers and add bases at 5' end of the growing polynucleotide ... and DNA polymerases can add nucleotides only at the 3' end of the growing polynucleotide chain
Description : The mechanism of antibacterial action of tetracycline involves (a) Binding to a component of the 50S ribosomal subunit (b) Inhibition of translocase activity (c) Blockade of binding of ... (d) Selective inhibition of ribosomal peptidyl transferases (e) Inhibition of DNA-dependent RNA polymerase
Last Answer : Ans: C
Description : Rifampin kills tubercle bacilli by: A. Binding to mycobacterial DNA dependent RNA polymerase B. Inhibiting mycobacterial DNA synthesis C. Inhibiting synthesis of mycolic acids in mycobacteria D. Damaging mycobacterial mitochondria
Last Answer : A. Binding to mycobacterial DNA dependent RNA polymerase
Description : The termination site for transcription is recognized by (A) α−Subunit of DNA-dependent RNA polymerase (B) β−Subunit of DNA-dependent RNA polymerase (C) Sigma factor (D) Rho factor
Description : The initiation site for transcription is recognized by (A) α−Subunit of DNA-dependent RNA polymerase (B) β−Subunit of DNA-dependent RNA polymerase (C) Sigma factor (D) Rho factor
Last Answer : Answer : C
Description : All of the following statements about RNA-dependent DNA polymerase are true except: (A) It synthesizes DNA using RNA as a template (B) It is also known as reverse transcriptase (C) It synthesizes DNA in 5’→3’ direction (D) It is present in all the viruses
Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus
Description : Binding of RNA polymerase holoenzyme to the promoter region of lac operon is facilitated by (A) Catabolite gene activator protein (CAP) (B) cAMP (C) CAP-cAMP complex (D) None of these
Description : The function of a repressor protein in an operon system is to prevent synthesis by binding to (A) The ribosome (B) A specific region of the operon preventing transcription of structural genes (C) The RNA polymerase (D) A specific region of the mRNA preventing translation to protein
Description : DNA fragments are sealed by (A) DNA polymerase II (B) DNA ligase (C) DNA gyrase (D) DNA topoisomerase II
Description : In the process of transcription in bacterial cells (A) Initiation requires rho protein (B) RNA polymerase incorporates methylated bases in correct sequence (C) Both the sigma unit and core ... RNA polymerase are required for accurate promotor site binding (D) Primase is necessary for initiation
Description : Another name for reverse transcriptase is (A) DNA dependent DNA polymerase (B) DNA dependent RNA polymerase (C) RNA dependent DNA polymerase (D) RNA dependent RNA polymerase
Description : The antibiotic which inhibits DNA dependent RNA polymerase is (A) Mitomycin C (B) Actinomycin d (C) Streptomycin (D) Puromycin
Description : α-Amanitin inhibits (A) DNA polymerase II of prokaryotes (B) DNA polymerase α of eukaryotes (C) RNA polymerase II of eukaryotes (D) RNA-dependent DNA polymerase
Description : DNA-dependent RNA polymerase requires the following for its catalytic activity: (A) Mg++ (B) Mn++ (C) Both (A) and (B) (D) None of these
Description : DNA-dependent RNA polymerase is a (A) Monomer (B) Dimer (C) Trimer (D) Tetramer
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 : Negative regulation of protein synthesis is accomplished by A- allosteric inhibition B- the binding of RNA polymerase to the promoter C- the binding of a repressor to the DNA D- the binding of a repressor to the RNA polymerase
Last Answer : the binding of a repressor to the DNA
Description : The role of molecular chaperones is to A-facilitate binding of ribosomes to mRNA B-degrade newly synthesized polypeptides that contain inaccurate sequences C-.facilitate binding of RNA polymerase to DNA D-aid a newly synthesized polypeptide in folding to its proper shape
Last Answer : -aid a newly synthesized polypeptide in folding to its proper shape
Last Answer : aid a newly synthesized polypeptide in folding to its proper shape
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 : 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 : DNA-dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the
Last Answer : DNA-dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the ... Antistrand C. Template strand D. Coding strand
Description : DNA-dependent RNA polymerase catalyses transcription on one strand of the DNA which is called the (a) template strand (b) coding strand (c) alpha strand (d) antistrand
Last Answer : (a) template strand
Description : DNA-dependent RNA polymerase catalyses transcription on one strand of the DNA which is called the (a) template strand (b) coding strand (c) alpha strand (d) antistrand.
Description : Which of the following statements is not true for retroviruses? (a) DNA is not present at any stage in the life cycle of retroviruses. (b) Retroviruses carry gene for RNA-dependent DNA ... mature retroviruses is RNA. (d) Retroviruses are causative agents for certain kinds of cancer in man.
Last Answer : (a) DNA is not present at any stage in the life cycle of retroviruses
Description : RNA polymerase holoenzyme binds to lac operon at the following site: (A) i gene (B) z gene (C) Operator locus (D) Promoter region
Description : The α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl tRNA occupying the P site. This reaction is catalysed by (A) DNA polymerase (B) RNA polymerase (C) Peptidyl transferase (D) DNA ligase
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 : Eukaryotic promoters contain (A) TATA box 25bp upstream of transcription start site (B) CAAT box 70-80 bp upstream of transcription start site (C) Both (A) and (B) (D) None of these
Description : During transcription, the DNA site at which RNA polymerase binds is called (a) promoter (b) regulator (c) receptor (d) enhancer.
Last Answer : d) enhancer
Last Answer : (a) promoter
Description : All of the following statements about eukaryotic promoters are true except (A) They may be located upstream or down stream from the structural gene (B) They have two consensus sequences ( ... (D) Mutations in promoter region can decrease the efficiency of transcription of the structural gene
Last Answer : Answer : A
Description : Template-directed DNA synthesis occurs in all the following except (A) The replication fork (B) Polymerase chain reaction (C) Growth of RNA tumor viruses (D) Expression of oncogenes
Description : Template-directed DNA synthesis occurs in all the following except (A) The replication fork (B) Polymerase chain reaction (C) Growth of RNA tumor viruses (D) Expression of oneogenes
Description : RNA directed DNA polymerase is (A) Replicase (B) Transcriptase (C) Reversetranscriptase (D) Polymerase–III
Description : DNA directed RNA polymerase is (A) Replicase (B) Transcriptase (C) Reverse transcriptase (D) Polymerase III
Description : Ribonucleotides of RNA primer are replaced by deoxyribonucleotides by the enzyme: (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these
Description : Deoxyribonucleotides are added to RNA primer by (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these
Description : RNA primer is formed by the enzyme: (A) Ribonuclease (B) Primase (C) DNA polymerase I (D) DNA polymerase III
Description : One of the first enzymes synthesized by many bacteriophage is __________ , an RNA dependent RNA polymerase A.RNA transcriptase B.RNA polymerase C.RNA ligase D.RNA replicase
Last Answer : D.RNA replicase
Description : The ‘rho’ (ρ) factor is involved (A) To increase the rate of RNA synthesis (B) In binding catabolite repressor to the promoter region (C) In proper termination of transcription (D) To allow proper initiation of transcriptide
Description : One of the following enzymes does not change glycogen synthase a to b. (A) Glycogen synthase kinases 3, 4, 5 (B) Ca2+ calmodulin phosphorylase kinase (C) Ca2+ calmodulin dependent protein kinase (D) Glycogen phosphorylase a
Last Answer : D