Free NEET Biology multiple-choice questions on Gene Regulation & Genomics. Attempt each question and reveal the answer with a full explanation.
E. coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because - They cannot synthesize functional beta galactosidase They cannot transport lactose from the medium into the cell The lac operon is constitutively active in these cells In the presence of glucose, E. coli cells do not utilize lactose If a geneticist uses the blind approach for sequencing the whole genome of an organism, followed by assignment of function to different segments, the methodology adopted by him is called as : Gene mapping Expressed sequence tags Bioinformatics Sequence annotation Expressed Sequence Tags (ESTs) refers to All genes that are expressed as RNA. All genes that are expressed as proteins. All genes whether expressed or unexpressed. Certain important expressed genes. The lactose present in the growth medium of bacteria is transported to the cell by the action of Beta-galactosidase Acetylase Permease Polymerase Which factor is important for termination of transcription? γ (gamma) α (alpha) σ (sigma) ρ (rho) Silencing of specific mRNA is possible via RNAi because of Non-complementary ssRNA Complementary dsRNA Inhibitory ssRNA Complementary tRNA Given below are two statements : Statement I : Transfer RNAs and ribosomal RNA do not interact with mRNA. Statement II : RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence. In the light of the above statements, choose the most appropriate answer from the options given below : Statement I is incorrect but statement II is correct Both statement I and statement II are correct Both statement I and statement II are incorrect Statement I is correct but statement II is incorrect Which chromosome in the human genome has the highest number of genes? Chromosome 10 Chromosome X Chromosome Y Chromosome 1 In the lac operon, the z gene codes for the repressor of lac operon transacetylase permease beta-galactosidase During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at the point. What is the sequence called - CAAT box GGTT box AAAT box TATA box A sequential expression of a set of human genes messenger RNA DNA sequence ribosome transfer RNA. During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle-like structure, what is it’s DNA-binding sequence? AATT CACC TATA TTAA Telomere repetitive DNA sequences control the function of eukaryotic chromosomes because they are RNA transcription initiator help chromosome pairing prevent chromosome loss act as replicons. Molecular basis of organ differentiation depends on the modulation in transcription by ribosome transcription factor anticodon RNA polymerase. Which enzyme/ s will be produced in a cell in which there is a nonsense mutation in the lac Y gene? (1) β-galactosidase (2) Lactose permease (3) Transacetylase (4) Lactose permease and transacetylase Which of the following statements is not true for cancer cells in relation to mutations ? (1) Mutations in proto-oncogenes accelerate the cell cycle. (2) Mutations destroy telomerase inhibitor. (3) Mutations inactive the cell control. (4) Mutations inhibit production of telomerase. Select the correct match Matthew Meselson and F. Stahl - Pisum sativum Alfred Hershey and Martha Chase - TMV Alec Jeffreys - Streptococcus pneumoniae Francois Jacob and Jacques Monod - Lac operon Match the following genes of the Lac operon with their respective products : array ll (a) i gene & (i) -galactosidase (b) z gene & (ii) Permease (c) a gene & (iii) Repressor (d) y gene & (iv) Transacetylase array Select the correct option. (a) (b) (c) (d) (1) (iii) (iv) (i) (ii) (2) (i) (iii) (ii) (iv) (3) (iii) (i) (ii) (iv) (4) (iii) (i) (iv) (ii) Expressed Sequence Tags (ESTs) refers to : (1) Novel DNA sequences (2) Genes expressed as RNA (3) Polypeptide expression (4) DNA polymorphism In an E. Coli strain i gene gets mutated and its product can not bind the inducer molecule. If growth medium is provided with lactose, what will be the outcome? z, y, a genes will be transcribed z, y, a genes will not be translated RNA polymerase will bind the promoter region Only z gene will get transcribed Match List I with List II. array ll List I & List II A. Gene ‘a’ & I. -galactosidase B. Gene ‘y’ & II. Transacetylase C. Gene ‘i’ & III. Permease D. Gene ‘z’ & IV. Repressor protein array Choose the correct answer from the options given below: (1) A-II, B-I, C-IV, D-III (2) A-II, B-III, C-IV, D-I (3) A-III, B-IV, C-I, D-II (4) A-III, B-I, C-IV, D-II Which of the following statements about lac-operon is correct? Gene i is constitutively expressed Lactose activates repressor to bind to the operator Genes i, z, y and a share single common promoter Galactose can act as an inducer of lac operon Differentiation of organs and tissues in a developing organism, is associated with differential expression of genes lethal mutations deletion of genes developmental mutations. One gene-one enzyme relationship was established for the first time in Salmonella typhimurium Escherichia coli Diplococcus pneumoniae Neurospora crassa. Which one of the following is wrongly matched? Transcription – Writing information from DNA to t-RNA. Translation – Using information in m-RNA to make protein Repressor protein – Binds to operator to stop enzyme synthesis. Operon – Structural genes, operator and promoter. Commonly used vectors for human genome sequencing are :- T-DNA BAC and YAC Expression Vectors T/A Cloning Vectors Which of the following is required as inducer(s) for the expression of Lac operon ? Glucose Galactose Lactose Lactose and galactose All of the following are part of an operon except an enhancer structural genes an operator a promoter DNA polymorphism forms the basis of : DNA finger printing Both genetic mapping and DNA finger printing Translation Genetic mapping