Birla Institute of Technology (BIT Mesra) 2007 B.E Experimental Techniques - Question Paper

BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE, PILANI
BIOLOGICAL SCIENCES GROUP
Experimental Techniques (BIO G642)
First Semester (2007-08) Quiz
MM. 30 Duration: 30 minutes 21.11.07
A. State True/ False:
i) 1% agarose will always provide better resolution than 0.7% agarose.
ii) E. coli strains incorporating recombination systems are preferred for gene cloning.
iii) In PCR, the most commonly used enzyme Taq DNA Polymerase has 3’ – 5’ exonuclease activity.
iv) TAE buffer has more buffering capacity than TBE.
v) Bgl II restriction enzyme having a restriction site as AGATCT can be used as isochizomer for Bam H one having restriction site as GGATCC.
vi) Polyacrylamide gels of 5- 10% are also used for separation of larger DNA fragments after a PCR reaction.
vii) Ouchterlony is a quantitative assay.
viii) Identity reaction occurs when 2 antigens share identical epitopes.
ix) During the process of cloning, if we cut the vector pBR322/ pUC18 with BamHI and also cut the genomic DNA with BamHI, after successful ligation and transformation in E.coli transforming host, the BamHI restriction site should regenerate in the open studying frame.
x) The 0.25 N HCl causes the depurinaton of DNA by breaking the N- glycosidic bond.

B. select the best/ accurate answer:
1. Salt precipitation in a nucleic acid extraction is performed to –
a) Precipitate nucleic acid; b) Remove protein contaminants; c) Precipitate phenol
d) Remove ethanol
2. An unknown volume of Ag can be determined by
a) Ouchterlony double diffusion; b) Radial Immunodiffusion; c) Sandwich ELISA; d) Both (b) and (c)
3. Polyacrylamide gels can’t be run in submerged state because
a) polyacrylamide gels have a comparatively low resiwstance
b) since isotachophoresis will be converted to electroendoosmosis
c) it is not cast by photopolymerisation
d) since the current will short circuit around the gell through the overlaying buffer
4. During electrophoresis if weak running buffer is used the electrical resistance rises due to
a) pH change; b) electrolyte depletion; c) both a and b; d) electroendosmosis
5. The use of formamide in RNA is for
a) complete denaturation of RNase; b) to maintain single stranded form of RNA
c) to maintain pH of RNA solution; d) to remove DNA
6. Ligase is more efficient at fusing
a) blunt ends; b) sticky ends; c) similar with both kind of ends; d) ligase does not fuse ends
7. Isoamylalcohol is used in DNA isolation as
a) denaturing agent; b) anti – foaming agent; c) solubilizes phenol; d) RNA separating agent
8. The PCR was invented by
a) Sevre Ochoa b) P.Saiki c) T. Faloona d) K. Mullis

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Experimental Techniques (BIO G642) Quiz
ans SHEET DATE: 21.11.07
MAX. MARKS: 30 NAME: Id. No.
A.
A 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. B 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.


1. 2.
3. 4.
5. a 5 b
9. Nylon membranes are much better than nitrocellulose membrane in southern transfer of DNA. Identify the false statement regarding this
a) Because nylon is more amenable to stripwashing in which the blot is cleared of the original probe by exposure to low salt temperature conditions for reprobing
b) Nylon does not require baking the fixed DNA onto the membrane as does nitrocellulose and this saves two hours and energy expenditure of incubation at 80? C
c) The DNA strongly binds to the positively charged groups of nylon membrane and UV fixation for 20 sec facilitate the process
d) None of these
10. In SDS PAGE the protein samples are heated with ß – mercaptoethanol or dithiothreitol
a) In order to overwhelm the proteins intrinsic charges
b) To break any S-S linkakes in the proteins
c) To condense the protein bands
d) None of these

C. Fill in the blanks:
1. Formaldehyde is used in RNA buffers to _______________.
2. _______________ gene is responsible for resistance to ampicillin.
3. __________ is used as the buffering agent in RNA gel electrophoresis.
4. Ratio of _____________ provide the purity of any nucleic acid preparation.
5. ___________ is the substrate for HRP and colouring agent used along is ______________.

Earning:   Approval pending.