Tiêu đề 28. Molecular Basis of Inheritance .pdf ✅

Chapter 28 Hjg`^pg\m=\ndnja Dic`mdo\i^` FACT/DEFINITION TYPE QUESTIONS 1. The two strands of DNA are held together by (a) peptide bonds (b) phosphodiester bonds (c) hydrogen bonds (d) S – S bonds 2. Nucleotide arrangement in DNA can be seen by (a) X-ray crystallography (b) electron microscope (c) ultracentrifuge (d) light microscope 3. Chargaff’s rules are applicable to (a) single stranded RNA. (b) single stranded DNA and RNA. (c) single stranded DNA. (d) double stranded DNA. 4. One turn of DNA possesses (a) one base pair (b) two base pairs (c) five base pairs (d) ten base pairs 5. Which of the following is correct for Watson and Crick’s model of DNA. It is duplex with (a) 10 base pairs and 3.4 Å distance for every turn. (b) 10 base pairs and 3.4 Å distance for each turn of spiral. (c) 20 base pairs and 34 Å for each turn. (d) None of the above 6. Information flow or central dogma of modern biology is (a) RNA ® Proteins ® DNA (b) DNA ® RNA ® RNA (c) RNA ® DNA ® Proteins (d) DNA ® RNA ® Proteins 7. Nucleosome is (a) intron interrupted DNA. (b) double helix DNA. (c) negatively charged DNA wrapped around positively charged histone octomer. (d) satellite DNA. 8. Genetic information is carried out by long chain molecule made up of (a) amino acids (b) enzymes (c) nucleotides (d) histone proteins 9. Histones are rich in (a) alanine and glycine (b) lysine and arginine (c) histidine and serine (d) cysteine and tyrosine 10. In Meselson and Stahl’s experiments, heavy DNA was distinguished from normal DNA by centrifugation in (a) CsOH gradient (b) 14NH4Cl (c) 15NH4Cl (d) CsCl gradient 11. In Streptococcus pneumoniae (a) virulent form is smooth. (b) virulent form is rough. (c) nonvirulent form is capsulated. (d) all forms are rough. 12. The scientists involved in discovery of DNA as chemical basis of heredity were (a) Hershey and Chase (b) Griffith and Avery (c) Avery, Mac Leod and McCarty (d) Watson and Crick 13. During infection of E. coli cells by bacteriophage T2 , (a) proteins are the only phage components that actually enter the infected cell. (b) both proteins and nucleic acids enter the cell. (c) only proteins from the infecting phage can also be detected in progeny phage. (d) only nucleic acids enter the cell. 14. If a double stranded DNA has 20% of cytosine, what will be the percentage of adenine in it? (a) 20% (b) 40% (c) 30% (d) 60% 15. In some viruses, RNA is present instead of DNA indicating that (a) their nucleic acid must combine with host DNA before replication. (b) they cannot replicate. (c) there is no hereditary information. (d) RNA can act to transfer heredity.
Molecular Basis of Inheritance 243 16. A bacterium grown over medium having radioactive 35S incorporates radioactivity in (a) carbohydrates (b) proteins (c) DNA (d) RNA 17. Leading strand during DNA replication is formed (a) continuously. (b) in short segments. (c) first. (d) ahead of replication. 18. DNA replication is (a) conservative and discontinuous. (b) semi-conservative and semi-discontinuous. (c) semi-conservative and discontinuous. (d) conservative. 19. Methyl guanosine triphosphate is added at 5' end of hn-RNA in a process of (a) tailing (b) splicing (c) capping (d) None of these 20. Genetic code is (a) triplet, universal, ambiguous and degenerate. (b) triplet, universal, non-ambiguous and non- degenerate. (c) triplet, universal, non-ambiguous and degenerate. (d) triplet, universal, ambiguous and non-degenerate. 21. Segments of mRNA removed during splicing are called ______. (a) introns (b) exons (c) promotor regions (d) integrator regions 22. Frame shift mutation occurs when (a) base is deleted or added. (b) base is added. (c) base is deleted. (d) anticodons are not present. 23. Initiation codon of protein synthesis (in eukaryotes) is (a) GUA (b) GCA (c) CCA (d) AUG 24. In eukaryotes, mRNA is synthesized with the aid of (a) RNA polymerase III. (b) RNA polmerase II. (c) RNA polymerase I. (d) reverse transcriptase. 25. Lactose operon produces enzymes (a) b-galactosidase, permease and glycogen synthetase. (b) b-galactosidase, permease and transacetylase. (c) permease, glycogen synthetase and transacetylase. (d) b-galactosidase, permease and phosphoglucose isomerase. 26. In Escherichia coli, lac operon is induced by (a) lactose (b) promotor gene (c) b-galactosidase (d) I-gene 27. Who proved that DNA is basic genetic material? (a) Griffith (b) Watson (c) Boveri and Sutton (d) Hershey and Chase 28. Lac operon is (a) arabinose operon (b) repressible operon (c) inducible operon (d) overlapping genes 29. Satellite DNA (a) is classified in many categories such as micro- satellites, minisatellites, etc. on the basis of base composition length of segments and number of repetitive units. (b) normally does not code for any protein. (c) shows polymorphism. (d) All of the above 30. Which process is used for amplication or multiplication of DNA for finger printing ? (a) Polymerse chain reaction (PCR) (b) Nesslerisation (c) Southern blotting (d) Northern blotting 31. Polymorphism in DNA sequence (a) is the basis of genetic mapping of human genome. (b) arises due to mutation. (c) is the basis of DNA finger printing. (d) All of the above 32. VNTRs are (a) Variable Number of Tandem Repeats. (b) Very Narrow Tandem Repeats. (c) Variable Non-cistronic Transposon Repeats. (d) Valuable Non-cistronic Transposon Regions. 33. SNP which is pronounced as “snips” stands for (a) Small Nuclear Protein (b) Single Nucleotide Particle (c) Single Nucleotide Polymorphism (d) Small Nicking Points 34. Human Genome Project (HGP) is closely associated with the rapid development of a new area in biology called as (a) biotechnology (b) bioinformatics (c) biogeography (d) bioscience STATEMENT TYPE QUESTIONS 35. Which of the following statement is correct about DNA polymerase ? (a) DNA polymerase can synthesize mRNA in the 3' to 5' direction. EduHulk 315
244 244244244244244244244 244 Biology (b) DNA polymerase can synthesize DNA in the 5' to 3' direction. (c) DNA polymerase can synthesize mRNA in the 5' to 3' direction. (d) DNA polymerase can synthesize DNA in the 3' to 5' direction. 36. Which of the following statement forms the basis of DNA fingerprinting? (a) The relative proportions of purines and pyrimidines in DNA. (b) Satellite DNA occurring as highly repeated short DNA segments. (c) The relative difference in the DNA occurrence in blood, skin and saliva. (d) The relative amount of DNA in the ridges and grooves of the fingerprints. 37. Select the correct statement regarding protein synthesis. (a) When the small subunit of the ribosome encounters an mRNA the process of translation begins. (b) Peptidase catalyses the formation of peptide bond. (c) UTRs are present between the start codon and stop codon. (d) At the end of translation, the release factor binds to the initiation codon. 38. Which of the following statement is incorrect? (a) VNTR belong to a class of mini satellite DNA. (b) DNA sequences work on the principle developed by F. Sanger. (c) HGP was coordinated by US Department of Energy and the National Institute of Health. (d) DNA fingerprinting involves identifying similarities in repetitive DNA. 39. Identify the incorrect statement about RNA. (a) RNA was the first genetic material to evolve in the living systems. (b) Apart from being a genetic material, it is also a catalyst. (c) DNA evolved from RNA with chemical modifications. (d) RNA being a catalyst is non-reactive and stable. 40. Identify the incorrect statement. (a) In prokaryotes, the structural gene is polycistronic. (b) In eukaryotes, structural genes have interrupted coding sequences. (c) Eukaryotes have split gene arrangement. (d) Intervening sequences appear in mature RNA. 41. Choose the incorrect statement regarding the observations drawn from the human genome project. (a) Repetitive sequences are stretches of RNA. (b) Less than 2 per cent of the genome codes for protein. (c) SNPs help in tracing human history. (d) Repetitive sequences make up a very large portion of the human genome. 42. Find out the incorrect statement. (a) Uracil is present in RNA at the place of thymine. (b) The complex of DNA and protein in chromosome is called chromatin. (c) Heterochromatin is the most highly condensed form of chromatin. (d) The process involved in the RNA formation on the DNA template is called replication. 43. Select the two correct statements out of the four (i–iv) 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 operator region. (iii) The z-gene codes for permease. (iv) This was elucidated by Francois Jacob and Jacque Monod. (a) (ii) and (iii) (b) (i) and (iii) (c) (ii) and (iv) (d) (i) and (ii) 44. How many of the given statements (i-iv) is/are correct? (i) In transcription, adenosine pairs with uracil. (ii) Regulation of lac operon by repressor is referred to as positive regulation. (iii) The human genome has approximately 50,000 genes. (iv) Haemophilia is a sex-linked recessive disease. (a) Two (b) Three (c) Four (d) One 45. Which of the following statements are correct? (i) r-RNA provides the template for synthesis of proteins. (ii) t-RNA brings amino acids and reads the genetic code. (iii) RNA polymerase binds to promoter and initiates transcription. (iv) A segment of DNA coding for polypeptide is called intron. (a) (i) and (iii) (b) (i) and (ii) (c) (i), (ii) and (iii) (d) (ii) and (iii) 46. Which of the following statements about RNA polymerase are correct? (i) RNA polymerase I transcribes rRNAs. (ii) RNA polymerase II transcribes snRNAs. (iii) RNA polymerase III transcribes hnRNA. (iv) RNA polymerase II transcribes hnRNAs. (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (i) and (iv) 47. Select the incorrect statement(s). (i) Six codons do not code for any amino acid. (ii) Codon is read in mRNA in a contiguous fashion. EduHulk
Molecular Basis of Inheritance 245 (iii) Three codons function as stop codons. (iv) The initiation codon AUG codes for methionine. (a) (i) only (b) (ii) only (c) (i), (ii) and (iv) (d) (i), (ii) and (iii) 48. Read the following statements and choose the incorrect statements. (i) Nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage. (ii) Phosphate group is linked to 5¢–OH of a nucleoside through phosphoester linkage. (iii) Two nucleosides are linked through 3¢–5¢N- glycosidic linkage. (iv) Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome. (v) The chromatin that is more densely packed and stains dark is called euchromatin. (a) (i) only (b) (iv) only (c) (iii) and (v) (d) (i), (ii) and (iii) ASSERTION/REASON TYPE QUESTIONS In the following questions, a statement of Assertion is followed by a statement of Reason. (a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion. (b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion. (c) If Assertion is true but Reason is false. (d) If both Assertion and Reason are false. 49. Assertion : Adenine cannot pair with cytosine Reason : Adenine and cytosine do not have a perfect match between hydrogen donor and hydrogen acceptor sites. Hence, they cannot pair. 50. Assertion : A single mRNA strand is capable of forming a number of different polypetide chains. Reason : The mRNA strand has terminator codon. 51. Assertion : The genetic code is degenerate. Reason : Most amino acids are coded by more than one codon. 52. Assertion : Replication and transcription occur in the nucleus but translation takes place in the cytoplasm. Reason : mRNA is transferred from the nucleus into cytoplasm where ribosomes and amino acids are available for protein synthesis. 53. Assertion : DNA fingerprinting is very well known for its application in paternity testing is case of disputes. Reason : It employs the principle of polymorphism in DNA sequences as the polymorphisms are inheritable from parent to children. MATCHING TYPE QUESTIONS 54. Match the enzymes (given in column I) with their function (given in column II) and choose the correct combination from the given options. Column - I Column - II A. Helicase I. Joining of nucleotides B. Gyrase II. Opening of DNA C. Primase III. Unwinding of DNA D. DNA polymerase III IV. RNA priming (a) A – II; B – I; C – III; D – IV (b) A – II; B – I; C – IV; D – III (c) A – IV; B – III; C – I; D – II (d) A – II; B – III; C – IV; D – I 55. Match the following and choose the correct combination from the given options. Column - I Column - II A. Splicing I. Lac operon B. Okazaki fragments II. Lagging strands C. Jacob and Monad III. Lactose D. Inducer IV. Removal of intron (a) A – IV; B – II; C – I; D – III (b) A – II; B – I; C – IV; D – III (c) A – IV; B – III; C – I; D – II (d) A – II; B – III; C – I; D – IV 56. Match the column-I with column-II and choose the correct combination from the given options. Column - I Column - II A. Operator site I. Binding site for RNA polymerase B. Promoter site II. Binding site for repressor molecule C. Structural gene III. Codes for enzyme protein D. Regulator gene IV. Codes for repressor molecules (a) A – II; B – I; C – III; D – IV (b) A – II; B – I; C – IV; D – III (c) A – IV; B – III; C – I; D – II (d) A – II; B – III; C – I; D – IV 57. Match the steps of protein by synthesis given in column- I with their feature given in column-II and select the correct combination from the given options. Column - I Column - II A. Termination I. Aminoacyl tRNA synthetase B. Translation II. Okazaki fragments C. Transcription III. GTP dependent release factor D. DNA replication IV. RNA polymerase EduHulk 315