AIPMT PMT MCQs Molecular Basis of Inheritance

1. Find out the sequence of binding of the following amino acyl-t-RNA complexes during translation to an m-RNA transcribed by a DNA segment having the base sequence 3′ ATACCCATGGGG 5′. Choose the answer showing the correct order of alphabets.

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2. In Griffith experiment, what would be the effect of the following conditions on the mice?
Form of Pneumococcus Effect on Mice Injected
I. Live, rough non-capsulated A
II. Live smooth capsulated B
III. Heat-killed smooth C
IV. Heat-killed smooth + live rough D Choose the correct option for their effect on mice.
(a) A-Survived, B—Died, C—Died, D-Survived
(b) A-Survived, B—Died, C- Survived, D—Died
(c) A- Died, B- Survived, C-Survived, D-Died
(d) A-Died, B-Survived, C—Died, D-Died

3. If a length of DNA has 45,000 base pairs, how many complete turns will the DNA molecule take?
(a) 4,500 (b) 45,000
(c) 45 (d) 450
4. Which one of the following group of codons is called as degenerate codons?
(a) UAA, UAG and UGA
(b) GUA, GUG, GCA, GCG and GAA
(c) UUC, UUG, CCU, CAA and CUG
(d) UUA, UUG, CUU, CUC and CUG
5. Arrange the various steps of DNA fingerprinting technique in the correct order.
(i) Separation of DNA fragments by electrophoresis.
(ii) Digestion of DNA by restriction endonucleases.
(iii) Hybridization using labelled VNTR probe.
(iv) Isolation of DNA.
(v) Detection of hybridized DNA fragments by auto radiography.
(vi) Transferring the separated DNA fragments to nitrocellulose membrane.
(a) (iv) (ii) -»(i) (vi) -»(iii) (v)
(b) (iv) -> (i) -> (ii) -> (iii) -> (vi) (v)
(c) (ii) ^ (i) > (iv) > (vi) > (iii) > (v)
(d) (iii) (v) (iv) (ii) (i) (vi)
6. The method developed by Matthew Meselson and Franklin Stahl to separate heavy DNA with ,5N from DNA with l4N, for providing evidence for semi-conservative replication of DNA is
(a) ion exchange chromatography
(b) density gradient centrifugation
(c) isopycnic centrifugation
(d) gel filtration.
(a) 4,500 (b) 45,000
(c) 45 (d) 450
4. Which one of the following group of codons is called as degenerate codons?
(a) UAA, UAG and UGA
(b) GUA, GUG, GCA, GCG and GAA
(c) UUC, UUG, CCU, CAA and CUG
(d) UUA, UUG, CUU, CUC and CUG
5. Arrange the various steps of DNA fingerprinting technique in the correct order.
(i) Separation of DNA fragments by electrophoresis.
(ii) Digestion of DNA by restriction endonucleases.
(iii) Hybridization using labelled VNTR probe.
(iv) Isolation of DNA.
(v) Detection of hybridized DNA fragments by auto radiography.
(vi) Transferring the separated DNA fragments to nitrocellulose membrane.
(a) (iv) (ii) -»(i) (vi) -»(iii) (v)
(b) (iv) -> (i) -> (ii) -> (iii) -> (vi) (v)
(c) (ii) ^ (i) > (iv) > (vi) > (iii) > (v)
(d) (iii) (v) (iv) (ii) (i) (vi)
6. The method developed by Matthew Meselson and Franklin Stahl to separate heavy DNA with ,5N from DNA with 14N, for providing evidence for semi-conservative replication of DNA is

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(a) ion exchange chromatography
(b) density gradient centrifugation
(c) isopycnic centrifugation
(d) gel filtration

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18. Which RNA carries the amino acids from the amino acid pool to mRNA during protein synthesis?
(a) rRNA (b) mRNA
(c) fRNA (d) hnRNA
19. Which of the following figures correctly represents the replication fork formed during DNA replication?

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20. Identify A, B, C and D in the given diagram of mRNA.

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21. The rule that in a DNA the amount of adenine equals to that of the thymine and that of guanine equals to that of cytosine is known as
(a) Allen’s rule (b) Jordan’s rule (c) Chargaff’s rule (d) Stahl’s rule.
22. In regulation of gene expression in prokaryotes
I. Lactose acts as a suppressor for the gene expression.
II. Tryptophan acts as an inducer for the gene expression.
III. Regulatory gene is the one that produces the repressor molecule.
Choose the correct options.
(a) Only I (b) Only II
(c) Only III (d) II and I
23. Read the following statements and select the correct option.
(i) Loosely packed and lightly stained region of chromatin is called as heterochromatin.
(ii) Densely packed and dark stained region of chromatin is called as euchromatin.
(iii) A typical nucleosome contains 200 bp of DNA helix.
(a) Statements (i) and (ii) are true, but statement (iii) is false
(b) Statements (i) and (ii) are false, but statement (iii) is true
(c) Statements (ii) and (iii) are true, but statement (i) is false
(d) All statements are true
24. Work of Beadle and Tatum on Neurospora crassa proved that
(a) replication of DNA is semi-conservative
(b) viruses have genetic material
(c) every gene is responsible for specific enzyme
(d) plant cells are totipotent.
25. Degeneration of DNA after heating can be studied by comparing
(a) A : T ratio
(b) G : C ratio
(c) Sugar: Phosphate (d) Number of nucleotides.
26. Splicing of RNA depends on
(a) hnmRNA
(b) exon
(c) intron
(d) self-splicing of intron.
27. Why does cytosine make pair with guanine and not with adenine ?
(a) C-A pair would be too wide to fit in the double helix.
(b) C and A are both polar.
(c) C-A pair would not reach across the double helix.
(d) the functional groups that form H-bond are not complementary between C and A.
28. The given flowchart shows central dogma reverse.

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29. The regulatory genes are located
(a) in between operator and the structural genes
(b) in the middle of the structural genes
(c) at the end of the structural genes
(d) upstream of the structural genes.
30. What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA ?
(a) A polypeptide of 24 amino acids will be formed.
(b) Two polypeptides of 24 and 25 amino acids will be formed.
(c) A polypeptide of 49 amino acids will be formed.
(d) A polypeptide of 25 amino acids will be formed.
31. Refer to the given figure of nucleosome and select the option that correctly identifies the parts A, B and C.

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32. A codon consists of 3 bases and there are 4 different kinds of bases in a nucleic acid altogether. How many codons will be there?
(a) 64 (b) 86
(c) 22 (d) 60
33. Match the following columns.

  Column I Column II
A Topoisomerase 1 Relaxes the DNA from its super-coiled nature.
B DNA gyrase 2 Relieves strain of unwinding by DNA helicase; this is a specific type of topoisomerase
C DNA ligase 3 Re-anneals the semiconservative strands and joins Okazaki fragments of the lagging strand.
D Primase 4 Provides a starting point of RNA (or DNA) for DNA polymerase to begin synthesis of the new DNA strand.
E Telomerase 5 Lengthens telomeric DNA by adding repetitive nucleotide sequences to the ends of eukaryotic chromosomes.

 

 

134. Choose the wrong statement.
(a) VNTR belong to a class of mini-satellite DNA.
(b) DNA sequencers work on the principle developed by Frederick Sanger.
(c) HGP was coordinated by US Department of Energy and the National Institute of Health.
(d) DNA finger printing involves identifying similarities in repetitive DNA.
35. If Meselson and Stahl’s experiment is continued for four generations in bacteria, the ratio of 15N/15N: 15N/14N: 14N/14N containing DNA in the fourth generation would be
(a) 1 : 1 : 0 (b) 1 :4 :0
(c) 0:1 :3 (d) 0:1 :7

36. Which of the following statements regarding ‘human genome’ is incorrect?
(a) Human genome consists of 3 x 109 bp and about 20,500 genes.
(b) The average gene size is 3000 bp and dystrophin is the largest known human gene.
(c) Chromosome 1 contains maximum (2968) number of genes and the Y-chromosome has the least (231) number of genes.
(d) Repeated (or repetitive) sequences a re not present in human genome.
37. The sequence of events mentioned below are symbolised by alphabets. Choose the correct answer where the alphabets are matched with the processes.
A                 B                C                     D
RNA -> DNA -» DNA -> mRNA -> Polypeptide
(a) A = replication, B = transformation,
C = transcription, D = translation
(b) A = reverse transcription, B = replication,
C = transcription, D = translation
(c) A = replication, B = transcription,
C = translation, D = transduction
(d) A = reverse transcription, B = translation,
C = transcription, D = replication.
38. Identify the correct match between the codons and coding functions.

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39. During transcription, mRNA provide …A…, fRNA brings …B… and reads genetic code and rRNAs play …C… and catalytic role during …D….
Choose the correct option for A, B, C and D.
(a) A-template, B-amino acid, C-structural, D-translation
(b) A-template, B-genetic codes, C-structural, D-translation
(c) A-template, B-genetic codes, C-translation, D-structural
(d) A-template, B-amino acid, C-translation, D-structural

40. Which of the following shows the correct positions of the phosphate (P), sugar (S) and base (B) molecules in the line diagrams representing structure of DNA?

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41. Repressible operon system is usually found in (i) pathways. The pathway’s end product serves as a
(ii) to activate the repressor, turn off enzyme synthesis and prevent overproduction of the end product of the pathway. Genes for this operon are usually switched (iii) and the repressor is synthesized in an (iv) form.

142. What is true about /RNA?
(a) It binds with an amino acid at it 3′ end.
(b) It has five double stranded regions.
(c) It has a codon at one end which recognizes the anticodon on messenger RNA.
(d) It looks like clover leaf in the three dimensional structure.
43. The first codon discovered by Nirenberg and Matthaei was
(a) CCC (b) GGG
(c) UUU (d) AAA.
44. Which of the following statements 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 hnRNA.
(a) (i) and (ii) are correct
(b) (i) and (iii) are correct
(c) (i), (ii) and (iv) are correct
(d) (i) and (iv) are correct
45. The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?
(a) Deletion of non-essential genes
(b) Super-coiling in nucleosome
(c) DNAase digestion
(d) Through elimination of repetitive DNA

Answers

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Comments ( 3 )
  1. gopal chavan
    April 6, 2016 at 5:09 pm
    Reply

    Notifi me plz

  2. Ajay
    August 10, 2016 at 2:16 pm
    Reply

    Keep notifying me

  3. Thenmozhi Mani
    September 30, 2016 at 6:50 pm
    Reply

    Good. But type correctly

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