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
Last Answer : Answer : C
Description : 3’→5’ Exonuclease activity of DNA polymerase I (A) Removes ribonucleotides (B) Adds deoxyribonucleotides (C) Corrects errors in replication (D) Hydrolyses DNA into mononucleotides
Description : RNA primer is formed by the enzyme: (A) Ribonuclease (B) Primase (C) DNA polymerase I (D) DNA polymerase III
Last Answer : Answer : B
Description : DNA is composed of repeating units of (a) ribonucleosides (b) deoxyribonucleosides (c) ribonucleotides (d) deoxyribonucleotides.
Last Answer : (d) deoxyribonucleotides.
Description : DNA polymerase III holoenzyme possesses (A) Polymerase activity (B) 3’→5’ Exonuclease activity (C) 5’→3’ Exonuclease and polymerase activities (D) 3’→5’ Exonuclease and polymerase activities
Last Answer : Answer : D
Description : Negative supercoils are introduced in DNA by (A) Helicase (B) DNA ligase (C) DNA gyrase (D) DNA polymerase III holoenzyme
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 : 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 : 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 enzyme adds complementary bases to the DNA template strand during replication. a. Ligase b. Helicase c. DNA polymerase III d. RNA polymerase
Last Answer : d. RNA polymerase
Description : The transcription initiation factor associated with the RNA polymerase holoenzyme in prokaryotes is (a) β (b) ω (c) σ (d) αI
Last Answer : c) σ (
Description : The removal of which enzyme affects the synthesis of hnRNA in eukaryotes a) RNA polymerase II b) RNA primase c) RNA polymerase III d) RNA polymerase I
Last Answer : a) RNA polymerase II
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 : The mechanism of synthesis of DNA and RNA are similar to all the following ways except (A) They involve release of pyrophosphate from each nucleotide added (B) They require activated nucleotide precursor and Mg2+ (C) The direction of synthesis is (D) They require a primer
Description : The normal function of restriction endonucleases is to (A) Excise introns from hrRNA (B) Polymerize nucleotides to form RNA (C) Remove primer from okazaki fragments (D) Protect bacteria from foreign DNA
Description : The mechanism of synthesis of DNA and RNA are similar in all the following ways except (A) They involve release of pyrophosphate from each nucleotide added (B) They require activated nucleotide precursor and Mg2+ (C) The direction of synthesis is 5’ → 3’ (D) They require a primer
Last Answer : Answer : A
Description : RNA synthesis requires (A) RNA primer (B) RNA template (C) DNA template (D) DNA primer
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 : 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 : In mammals, synthesis of mRNA is catalysed by (A) RNA polymerase I (B) RNA polymerase II (C) RNA polymerase III(D) RNA polymerase IV
Description : The following statement(s) is/are true concerning newer detection methods of systemic infection. a. Enzyme-linked immunosorbent assay (ELISA) is a rapid immunologic assay used for ... detected using advanced molecular techniques include cytomegalovirus (CMV) and human immunodeficiency virus (HIV)
Last Answer : Answer: a, b, c, d Although the classic detection of infection based on clinical signs of infection and bacterial culture remain the most common clinical tools, increasing ... including CMV and HIV. Furthermore, preliminary investigations into possible detection of fungal pathogens are underway
Description : An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix ... nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand
Last Answer : Answer: c Transcription of a gene begins at an initiation site associated with a specific DNA sequence, termed a promoter region. After binding to DNA, the RNA polymerase opens up a short ... different proteins from the same gene. mRNA is exported from the nucleus only after processing is complete
Description : Name the enzyme that facilitates opening of DNA helix during transcription. (a) DNA ligase (b) DNA helicase (c) DNA polymerase (d) RNA polymerase
Last Answer : b) DNA helicase
Description : In RNA molecule guanine content does not necessarily equal its cytosine content nor does its adenine content necessarily equal its uracil content since it is a (A) Single strand molecule ( ... stranded molecule (C) Double stranded helical molecule (D) Polymer of purine and pyrimidine ribonucleotides
Description : The enzyme used in polymerase chain reaction (PCR) is (A) Taq polymerase (B) RNA polymerase (C) Ribonuclease (D) Endonuclease
Description : Ciprofloxacin inhibits (A) DNA topisomerase II (B) DNA polymerase I (C) DNA polymerase III (D) DNA gyrase
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 : 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 : 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 : 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 : The antibiotic which inhibits DNA dependent RNA polymerase is (A) Mitomycin C (B) Actinomycin d (C) Streptomycin (D) Puromycin
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
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 : 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 : 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 : 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 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 : 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 : What characteristics of DNA polymerase III make it an ideal enzyme for replicating the whole genome?
Last Answer : The key features of DNA polymerase III are its catalytic potency, its fidelity, and its processivity. It is able to catalyze the addition of ~103 bases per second, compared to only about 10 per ... to dissociate from the template strand after synthesis of short (tens of bases) stretches of DNA.
Description : Mammalian RNA polymerase III synthesises (A) rRNA (B) mRNA (C) tRNA (D) hnRNA
Description : Match the following RNA polymerase with their transcribed products : 1. RNA polymerase I (i) tRNA 2. RNA polymerase II (ii) rRNA 3. RNA polymerase III (iii) hnRNA Select the correct option from the following : (a) 1-i, 2-iii, 3-ii (b) 1-i, 2-ii, 3-iii (c) 1-ii, 2-iii, 3-i (d) 1-iii, 2-ii, 3-i
Last Answer : (b) 1-i, 2-ii, 3-iii
Description : The RNA molecules from a single strand of ribonucleotides of (a) Adenine, guanine, cytosins and uracil (b) Adenine, guanine and cytosins (c) Adenine and guanine (d) None of the above
Last Answer : Ans:(a)
Description : In DNA replication the enzyme required in the first step is (A) DNA directed polymerase (B) Unwinding proteins (C) DNA polymerase (D) DNA ligase
Description : Carbonic anhydrase enzyme has maximum turn over number (36 million). Minimum turn over number for an enzyme: (A) DNA polymerase (B) Lysozyme (C) Penicillase (D) Lactase dehydrogenase
Description : After formation of replication fork (A) Both the new strands are synthesized discontinuously (B) One strand is synthesized continuously and the other discontinuously (C) Both the new strands are synthesized continuously (D) RNA primer is required only for the synthesis of one new strand