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 : 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
Last Answer : Answer : B
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 : Select the two correct statements out of the four (i - iv) statements given below about lac operon. (i) Glucose or galactose may bind with the repressor and inactivate it. (ii) In the absence of lactose, the repressor binds with the ... (iii) (b) (i) and (iii) (c) (ii) and (iv) (d) (i) and (ii)
Last Answer : (c) (ii) and (iv)
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 : 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 : Which one of the following is not a part of a transcription unit in DNA? (a) The inducer (b) A terminator (c) A promoter (d) The structural gene
Last Answer : (c) A promoter
Last Answer : (a) The inducer
Description : Which one of the following is not a part of a transcription unit in DNA ? (1) The structural gene (2) The inducer (3) A terminator (4) A promoter
Last Answer : (2) The inducer
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 : 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 : If an antibiotic binds to a 50S subunit, what cellular process will be inhibited? a. DNA replication b. Intron excision c. Translation d. Transcription
Last Answer : c. Translation
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
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
Description : In the ’lac operon’ concept, which of the following is a protein? (A) Operator (B) Repressor (C) Inducer (D) Vector
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
Last Answer : Answer : D
Description : In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor
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 : In Lac-operon, repressor protein binds to
Last Answer : In Lac-operon, repressor protein binds to A. Regulator gene B. Operator gene C. Promoter gene D. Structural gene
Description : .In negative operon, (a) co-repressor binds with repressor (b) co-repressor does not bind with repressor (c) co-repressor binds with inducer (d) cAMP have negative effect on lac operon. (
Last Answer : co-repressor binds with repressor
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 : Following statements describe the characteristics of the enzyme restriction endonuclease. Identify the incorrect statement. (a) The enzyme recognises a specific palindromic nucleotide sequence in the DNA. (b) ... (d) The enzyme cuts the sugar-phosphate backbone at specific sites on each strand.
Last Answer : (c) The enzyme binds DNA at specific sites and cuts only one of the two strands.
Description : How does the repressor protein prevent transcription? -Biology
Last Answer : answer:
Description : .Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.
Last Answer : (d) negative and inducible because repressor protein prevents transcription.
Description : Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.
Description : When does the lac repressor protein bind to the operator? -Biology
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 : The smallest unit of DNA capable of coding for the synthesis of a polypeptide is (A) Operon (B) Repressor gene (C) Cistron (D) Replicon
Description : During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG then the nucleotide sequence in the mRNA would be (a) TATGC (b) TCTGG (c) UAUGC (d) UATGC.
Last Answer : (c) UAUGC
Description : Transposons are of particular significance because they a. often contain genes for antibiotic resistance. b. inhibit the effects of overlapping genes. c. come in pairs and often are associated with viruses. d. regulate gene transcription in bacterial cells.
Last Answer : a. often contain genes for antibiotic resistance.
Description : Actinomycin D binds to (A) Double stranded DNA (B) Single stranded DNA (C) Single stranded RNA (D) DNA-RNA hybrid
Description : Genes that are involved in turning on or off the transcription of a set of structural genes are called (a) redundant genes (b) regulatory genes (c) polymorphic genes (d) operator genes.
Last Answer : (d) operator genes.
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 : 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 sequence of events in muscle contraction a. action potential depolarise the T-tubules b. depolarisation of T-tubules release calcium from sarcoplasmic reticulum c. calcium binds to the troponin-tropomycin complex d. all above
Last Answer : all above
Description : In the process of transcription, the flow of genetic information is from (A) DNA to DNA (B) DNA to protein (C) RNA to protein (D) DNA to RNA
Description : Transcription is the formation of (A) DNA from a parent DNA (B) mRNA from a parent mRNA (C) pre mRNA from DNA (D) protein through mRNA
Description : Proteins which interact with DNA and affect the rate of transcription possess the following structural motif: (A) Helix-turn-helix motif (B) Zinc finger motif (C) Leucine zipper motif (D) All of these
Description : Rifampicin inhibits (A) Unwinding of DNA (B) Initiation of replication (C) Initiation of translation (D) Initiation of transcription
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 : Synthesis of RNA and a DNA template is known as (A) Replication (B) Translation (C) Transcription (D) Mutation
Description : Synthesis of DNA is also known as (A) Duplication (B) Replication (C) Transcription (D) Translation