Description : Insertion of a base in a gene can cause (A) Change in reading frame (B) Garbled amino acid sequence in the encoded protein (C) Premature termination of translation (D) All of these
Last Answer : Answer : D
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 : Suppressor tRNAs can neutralize the effects of mutations in (A) Structural genes (B) Promoter regions (C) Enhancer elements(D) All of these
Description : Suppressor mutations occur in (A) Structural genes (B) Promoter regions (C) Silencer elements (D) Anticodons of tRNA
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 : 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 : 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 : 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
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 : 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 is NOT part of an operon? a. Regulatory gene b. Operator c. Promoter d. Structural genes
Last Answer : d. Structural genes
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 : 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 : 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 : Which of the following is transcribed during repression? (A) Structural gene (B) Promoter gene (C) Regulator gene (D) Operator gene
Description : The gene which is transcribed during repression is (A) Structural (B) Regulator (C) Promoter (D) Operator
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 : .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 : All of the following are part of an operon except (a) an operator (b) structural genes (c) an enhancer (d) a promoter.
Last Answer : (c) an enhancer
Description : How would the transcription of the eukaryotic gene be affected if a replication error changed the nucleotide sequence of the termination signal for that gene?
Last Answer : Extra long proteins are likely to fold improperly and notfunction correctly. The overall health of the individual would bedestroyed.
Description : Nondisjunction of a chromosome results in which of the following diagnoses? a) Down Syndrome When a pair of chromosomes fails to separate completely and creates a sperm or oocyte that contains two ... genetic condition that may occur in a single family member as a result of spontaneous mutation.
Last Answer : a) Down Syndrome When a pair of chromosomes fails to separate completely and creates a sperm or oocyte that contains two copies of a particular chromosome (nondisjunction) Down syndrome results from three number 21 chromosomes.
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 : All of the following statements about puromycin are true except (A) It is an alanyl tRNA analogue (B) It causes premature termination of protein synthesis (C) It inhibits protein synthesis in prokaryotes (D) It inhibits protein synthesis in eukaryotes
Description : Puromycin causes premature chain termination in (A) Prokaryotes (B) Eukaryotes (C) Both (A) and (B) (D) None of these
Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination
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 : Which one of the following statements is true? a. Plasmids are circular molecules of RNA. b. RNA replicates by a conservative method of replication. c. Deletions or insertions of a ... reading frameshift during translation. d. Okazaki fragments are removed from a RNA before translation occurs.
Last Answer : c. Deletions or insertions of a nucleotide in a gene will cause a reading frameshift during translation.
Description : The final step of gene expression is protein synthesis, which is also known as A- replication B- translation C- transcription D- none of these
Last Answer : translation
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
Description : Chromatin has two different regions, euchromatin and heterochromatin. One of these regions is highly condensed and considered an inactive region whereas the other is less condensed so it is more ... for transcription. Which of these regions would contain genes that are being transcribed often?
Last Answer : Euchromatin. Euchromatin is less condensly packaged allowing for easier access by transcription factors and polymerases. Heterochromatin is a region of condensed packaging and considered an inactive region.
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 : .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 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 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 : Which of the following is a nontranslated sequence located between the transcription andthetranslation start site? A-Ending frame B- Leader sequence C- Trailer sequence D-Reading frame
Last Answer : Leader sequence
Description : tRNA genes have (A) Upstream promoters (B) Downstream promoters (C) Intragenic promoters (D) No promoters
Description : All the following statements about restriction fragment length polymorphism are true except (A) It results from mutations in restriction sites (B) Mutations in restriction sites can occur in coding or non- ... It is inherited in Mendelian fashion (D) It can be used to diagnose any genetic disease
Description : All the following statements about retino blastoma are true except (A) At least two mutations are required for its development (B) One mutation can be inherited from a parent (C) Children ... mutation develop retinoblastoma at a younger age (D) RB 1 gene promotes the development of retinoblastoma
Description : Ras proto-oncogene is converted into oncogene by (A) A point mutation (B) Chromosomal translocation (C) Insertion of a viral promoter upstream of the gene (D) Gene amplification
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 : Sigma and Rho factors are required for (A) Replication (B) Transcription (C) Translation (D) Polymerisation