Description : After termination of the synthesis of RNA molecule, the core enzymes separate from the DNA template. The core enzymes then recognize a promoter at which the synthesis of a new RNA molecule commences, with the assistance of (A) Rho (ρ) factor (B) δ factor (C) β factor (D) σ factor
Last Answer : Answer : D
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 : Termination of the synthesis of the RNA molecule is signaled by a sequence in the template strand of the DNA molecule, a signal that is recognized by a termination protein, the (A) Rho (ρ) factor (B) σ factor (C) δ factor (D) ε factor
Last Answer : Answer : A
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
Last Answer : Answer : C
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
Last Answer : Answer : B
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 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 : 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 : 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 : Transcription of structural genes of lac operon is prevented by binding of the repressor tetramer to (A) i gene (B) Operator locus (C) Promoter (D) z gene
Description : .In protein synthesis, the polymerisation of amino acids involves three steps. Which one of the following is not involved in the polymerisation of protein ? (a) Termination (b) Initiation (c) Elongation (d) Transcription
Last Answer : (a) Termination
Description : In protein synthesis, the polymerisation of amino acids involves three steps. Which one of the following is not involved in the polymerisation of protein ? (a) Termination (b) Initiation (c) Elongation (d) Transcription
Last Answer : Transcription
Description : Which one of the following is wrongly matched? (a) Transcription - Writing information from DNA to tRNA. (b) Translation - Using information in mRNA to make protein. (c) Repressor protein - Binds to operator to stop enzyme synthesis. (d) Operon - Structural genes, operator and promoter.
Last Answer : (c) Repressor protein - Binds to operator to stop enzyme synthesis.
Last Answer : (d) Operon - Structural genes, operator and 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
Description : Mutations in promoter regions of genes can cause (A) Premature termination of translation (B) Change in reading frame of downstream structural gene (C) Decreased efficiency of transcription (D) All of these
Description : Synthesis of RNA molecule is terminated by a signal which is recognised by (A) α-factor (B) β-factor (C) δ-factor (D) ρ
Description : In pKO1 plasmid, galactose kinase gene is a reporter gene which lacks ___________ gene. a. Initiation codon b. Promoter c. Activator d. Termination
Last Answer : b. Promoter
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 : Nonsense codons bring about (A) Amino acid activation (B) Initiation of protein synthesis (C) Termination of protein synthesis (D) Elongation of polypeptide chains
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 region of the Lac operon which must be free from structural gene transcription to occur is (A) The operator locus (B) The promoter site (C) The ‘a’ gene (D) The ‘i’ gene
Description : To commence structural gene transcription the region which should be free on lac operation is (A) Promoter site (B) Operator locus (C) Y gene (D) A gene
Description : Initiation of protein synthesis begins with binding of (A) 40S ribosomal unit on mRNA (B) 60S ribosomal unit (C) Charging of tRNA with specific amino acid (D) Attachment of aminoacyl tRNA on mRNA
Description : Sigma and Rho factors are required for (A) Replication (B) Transcription (C) Translation (D) Polymerisation
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 : Translocase is an enzyme required in the process of (A) DNA replication (B) RNA synthesis (C) Initiation of protein synthesis (D) Elongation of peptides
Description : A chain growth polymerisation reaction consists of three different types of reaction namely initiation reaction, propagation reaction & termination reaction. Chain growth polymerisation reaction is not involved ... Siloxane elastomers (B) Polyamides (C) Vinyl polymers (D) Urea-formaldehyde resins
Last Answer : (D) Urea-formaldehyde resins
Description : In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor
Description : The ribosome binding site A- forms a stem-loop structure in the RNA B- is located upstream of the promoter sequence C- .is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein
Last Answer : .is located immediately upstream of the start codon
Description : The rivosome binding site A- forms a sltem- loop structure in the RNA B- is located upstream of the promoter sequence C- is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein
Last Answer : is located immediately upstream of the start codon
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 : Which binding is inhibited by pactamycin? A- Aminoacyl-tRNA to the A-site of 30S subunit B- Initiator-tRNA to 30S/40S initiation complexes C- Peptidyl t-RNA to the 50S subunit D- Formation of peptide bond in P site
Last Answer : Initiator-tRNA to 30S/40S initiation complexes
Description : Synthesis of RNA and a DNA template is known as (A) Replication (B) Translation (C) Transcription (D) Mutation
Description : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
Description : Repressor binds to DNA sequence and regulate the transcription. This sequence is called (A) Attenuator (B) Terminator (C) Anti terminator (D) Operator
Description : The minimum effective size of an operator for lac repressor binding is (A) 5 base pairs (B) 10 base pairs (C) 15 base pairs (D) 17 base pairs
Description : The formation of initiation complex during protein synthesis requires a factor: (A) IF-III (B) EF-I (C) EF-II (D) IF-I
Description : In E. coli, during lactose metabolism repressor binds to (a) regulator gene (b) operator gene (c) structural gene (d) promoter gen
Last Answer : (b) operator gene
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 : Rifampicin inhibits (A) Unwinding of DNA (B) Initiation of replication (C) Initiation of translation (D) Initiation of transcription
Description : Which one of the following binds to specific nucleotide sequences that are upstream and most distant from the start site? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction
Description : Which one of the following binds to specific nucleotide sequences? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction
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 : Transcription means the synthesis of – (1) Lipids (2) Protein (3) DNA (4) RNA
Last Answer : (3) DNA Explanation: Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme, RNA polymerase. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, anti-parallel RNA strand.
Description : .After a mutation at a genetic locus the character of an organism changes due to change in (a) protein structure (b) DNA replication (c) protein synthesis pattern (d) RNA transcription pattern.
Last Answer : (d) RNA transcription pattern.
Description : After a mutation at a genetic locus the character of an organism changes due to change in (a) protein structure (b) DNA replication (c) protein synthesis pattern (d) RNA transcription pattern.
Last Answer : a) protein structure