Description : Which one of the following binds to specific nucleotide sequences? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction
Last Answer : Answer : A
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 : 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 : Select the incorrect statement out of the five given below about lac operon when Lactose is present in the medium. a) Gene - A gets transcribed into mRNA which produces β-galactoside permease b) ... polymerase transcribe Z-gene, Y-gene and A-gene e) Allolactose is the inducer of lac operon
Last Answer : Gene – A gets transcribed into mRNA which produces β-galactoside permease b) Inducer-Repressor complex is formed
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 : DNA contains some palindromic sequences which (A) Mark the site for the formation of replication forks (B) Direct DNA polymerase to turn back to replicate the other strand (C) Are recognized by restriction enzymes (D) Are found only in bacterial DNA
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 : 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 : RNA polymerase holoenzyme binds to lac operon at the following site: (A) i gene (B) z gene (C) Operator locus (D) Promoter region
Description : Restriction endonucleases are enzymes which (a) make cuts at specific positions within the DNA molecule (b) recognize a specific nucleotide sequence for binding of DNA ligase (c) restrict the action of the enzyme DNA polymerase (d) remove nucleotides from the ends of the DNA molecule
Last Answer : (a) make cuts at specific positions within the DNA molecule
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 : 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 : Restriction endonucleases can recognise (A) Palindromic sequences (B) Chimeric DNA (C) DNA-RNA hybrids (D) Homopolymer sequences
Description : In the ’lac operon’ concept, which of the following is a protein? (A) Operator (B) Repressor (C) Inducer (D) Vector
Description : Positive control of induction is best described as a control system in which an operon functions (A) Unless it is switched off by a derepressed repressor protein (B) Only after a repressor protein is ... on (D) Only after an inducer protein, which is activated by an inducer, switch it on
Description : In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor
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 : 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 : At a chromosome replication fork, the lagging strand consists of__ That is joined by___. a. RNA sequences; DNA ligase b. Okazaki Fragments; RNA Polymerase c. RNA sequences; ribosomes d. Okazaki fragments; DNA ligase
Last Answer : d. Okazaki fragments; DNA ligase
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 : Repressor binds to DNA sequence and regulate the transcription. This sequence is called (A) Attenuator (B) Terminator (C) Anti terminator (D) Operator
Description : A seals sticky ends of recombinant DNA segments. a. DNA Ligase b. restriction endonuclease c. protease d. RNA polymerase
Last Answer : b. restriction endonuclease
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 : The genetic code operates via (A) The protein moiety of DNA (B) The base sequences of DNA (C) The nucleotide sequence of mRNA (D) The base sequence of tRNA
Description : Restriction endonucleases (A) Cut RNA chains at specific locations (B) Excise introns from hnRNA (C) Remove Okazaki fragments (D) Act as defensive enzymes to protect the host bacterial DNA from DNA of foreign organisms
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 : 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.
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)
Last Answer : (d) Operon - Structural genes, operator and promoter
Description : All of the following statements about restriction endonucleases are true except: (A) They are present in bacteria (B) They act on double stranded DNA (C) They recognize palindromic sequences (D) They always produce sticky ends
Description : Polymerase chain reaction can rapidly amplify DNA sequences of the size (A) Upto 10 kilobases (B) Upto 45 kilobases (C) Upto 100 kilobases(D) Upto 1,000 kilobases
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 : 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 : 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 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 : 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 : 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 : In the regulation of genes: a. more than 90% of the base sequences in human DNA have not known function b. extrons are the part of the gene that code for amino acids found in the final proteins. c. introns usually begins with the nucleotide sequence GT d. all above
Last Answer : all above
Description : Which of the following nucleotide sequences contains 4 pyrimidine bases? (a) GATCAATGC (b) GCUAGACAA (c) UAGCGGUAA (d) Both (b) and (c)
Last Answer : a) GATCAATGC
Description : What information can be generated by interrupted mating experiments? A- Levels of DNA homology B- Bacterial genome maps C- DNA nucleotide sequences D- Proteomics of the bacteria
Last Answer : Bacterial genome maps
Description : Evolutionary relationships between groups of organisms are determined using which of Thefollowing type of information? A- Comparisons of nucleotide sequences B- .Comparisons of biochemical pathways C- Comparisons of structural features D- All of the above
Last Answer : All of the above
Description : Actinomycin D binds to (A) Double stranded DNA (B) Single stranded DNA (C) Single stranded RNA (D) DNA-RNA hybrid
Description : Satellite DNA contains (A) Highly repetitive sequences (B) Moderately repetitive sequences (C) Non-repetitive sequences (D) DNA-RNA hybrids