Description : .All of the following are part of an operon except (a) an operator (b) structural genes (c) an enhancer (d) a promoter.
Last Answer : d) a promoter.
Description : Which one of the following is NOT part of an operon? a. Regulatory gene b. Operator c. Promoter d. Structural genes
Last Answer : d. Structural genes
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 : Lac operon is a cluster of (A) Three structural genes (B) Three structural genes and their promoter (C) A regulatory gene, an operator and a promoter (D) A regulatory gene, an operator, a promoter and three structural genes
Last Answer : Answer : D
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 : Suppressor tRNAs can neutralize the effects of mutations in (A) Structural genes (B) Promoter regions (C) Enhancer elements(D) All of these
Last Answer : Answer : A
Description : The coding sequences in lac operon include (A) i gene (B) i gene, operator locus and promoter (C) z, y and a genes (D) i, z, y and a genes
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 : Lac operon of E. coli contains _______ is continuity. (A) Regulator and operator genes only (B) Operator and structural genes only (C) Regular and structural genes only (D) Regulator, operator and structural genes
Description : Expression of structural genes of lac operon is affected by all the following except (A) Lactose or its analogues (B) Repressor tetramer (C) cAMP (D) CAP-cAMP complex
Last Answer : Answer : C
Description : Enhancer elements have all the following features except (A) They increase gene expression through a promoter (B) Each enhancer activates a specific promoter (C) They may be located far away from the promoter (D) They may be upstream or downstream from the promoter
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 : RNA polymerase holoenzyme binds to lac operon at the following site: (A) i gene (B) z gene (C) Operator locus (D) Promoter region
Description : In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor
Description : Which of the following is transcribed during repression? (A) Structural gene (B) Promoter gene (C) Regulator gene (D) Operator 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 gene which is transcribed during repression is (A) Structural (B) Regulator (C) Promoter (D) Operator
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 regulatory i gene of lac operon (A) Is inhibited by lacotse (B) Is inhibited by its own product, the repressor protein (C) Forms a regulatory protein which increases the expression of downstream structural genes (D) Is constitutively expressed
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 : .The lac operon consists of (a) four regulatory genes only (b) one regulatory gene and three structural genes (c) two regulatory genes and two structural genes (d) three regulatory genes and three structural genes.
Last Answer : (b) one regulatory gene and three structural genes
Description : The structural genes of lac operon transcribe mRNA which is a) polycistronic b) replicative c) monokaryotic d) monocistronic
Last Answer : a) polycistronic
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 : Suppressor mutations occur in (A) Structural genes (B) Promoter regions (C) Silencer elements (D) Anticodons of tRNA
Description : In transgenics, expression of transgene in target tissue is determined by (a) enhancer (b) transgene (c) promoter (d) reporter.
Last Answer : (d) reporter.
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 : 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 : 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 : 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 : Lac operon’ in E. coli, is induced by (a) ‘I’ gene (b) promoter gene (c) β-galactosidase (d) lactose.
Last Answer : (c) β-galactosidase
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 : 8. Non coding sequences present within a gene is called: (a) Exon (b) Operon (c) Promoter (d) Intron
Last Answer : (d) Intron
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 : In the ’lac operon’ concept, which of the following is a protein? (A) Operator (B) Repressor (C) Inducer (D) Vector
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 : What genes are parts of the lac operon? -Biology
Last Answer : answer:
Description : Which of the following genes of the E.coli “Lac operon” codes for a constitutive protein? (A) The ‘a’ gene (B) The ‘i’ gene (C) The ‘c’ gene (D) The ‘z’ gene
Description : The enzymes encoded by z, y and a genes of lac operon are inducible, and their inducer is (A) Lactose (B) Allo-lactose (C) Catabolite gene activator protein (D) All of these
Description : Trancription of z, y and a genes of lac operon is prevented by (A) Lactose (B) Allo-lactose (C) Repressor (D) cAMP
Description : Lac operon is a cluster of genes present in (A) Human beings (B) E. coli (C) Lambda phage (D) All of these
Description : A group of genes whose activity is coordinated by a DNA site is – (1) operon (2) cistron (3) polysome (4) polypeptide
Last Answer : (1) operon Explanation: The operon is defined as a group of genes whose activity is coordinated by a DNA site. An operon is a functioning unit of genomic DNA containing a cluster ... together in the cytoplasm, or undergo trans-splicing to create monocistronic mR-NAs that are translated separately.
Description : Match the following genes of the Lac operon with their respective products. (A) i gene (i) b-galactosidase (B) z gene (ii) Permease (C) a gene (iii)Repressor (D) y gene (iv) Transacetylase Select the correct option. (A) (B) (C) ( ... ) (iii) (ii) (iv) (c) (iii) (i) (ii) (iv) (d) (iii) (i) (iv) (ii)
Last Answer : (a) (iii) (iv) (i) (ii)
Description : The lac operon is an example of (a) repressible operon (b) overlapping genes (c) arabinose operon (d) inducible operon.
Last Answer : (d) inducible operon.