Gene Manipulation Questions and Answers – Basic Laboratory Techniques – 2

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This set of Gene Manipulation Questions and Answers for Freshers focuses on “Basic Laboratory Techniques – 2”.

1. The technique of sucrose gradients was later superseded by __________
a) Electroporation
b) Electrodialysis
c) Gel electrophoresis
d) Biolistics
View Answer

Answer: c
Explanation: The first experiments of cutting and joining DNA were monitored by velocity sedimentation in sucrose gradient; this has been entirely superseded by gel electrophoresis.
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2. Gel electrophoresis is not used as a purification technique.
a) True
b) False
View Answer

Answer: b
Explanation: Gel electrophoresis is not only used as an analytical method, but it is also routinely used preparatively for the purification of DNA.

3. Polyacrylamide in Gel electrophoresis technique is preferred for _______________
a) Smaller DNA
b) Bigger chunks
c) Proteins
d) Sucrose
View Answer

Answer: a
Explanation: Agarose is convenient for separating DNA fragments ranging a few hundred base pairs in size and polyacrylamide is preferred for smaller DNA fragments.

4. The average pore size of an agarose gel depends on _______________
a) Casting tray
b) Buffer composition
c) Amount
d) Protein
View Answer

Answer: b
Explanation: An agarose gel is a complex network of polymeric molecules whose average pore size depends on the buffer composition.

5. DNA molecules in an electrophoresis gel exhibit which behavior?
a) Black body
b) Inelastic
c) Elastic
d) Reputation
View Answer

Answer: c
Explanation: DNA molecules display elastic behavior by stretching in the direction of the applied field and then contracting into dense balls.

6. Molecules greater than what size cannot be separated without using electric field?
a) 1 kb
b) 2 kb
c) 10 kb
d) 20 kb
View Answer

Answer: d
Explanation: With molecules about 20 kb in size, it is difficult to separate molecules without recourse to pulsed electric fields.
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7. PFGE was developed in which year?
a) 1970
b) 1984
c) 1950
d) 1944
View Answer

Answer: b
Explanation: In pulsed-field gel electrophoresis (PFGE), developed by Schwartz and Cantor 1984, molecules as large as 10 Mb can be separated in agarose gels.

8. In PFGE, the direction of DNA molecules is periodically ________
a) Hindered
b) Changed
c) Paused
d) Slowed
View Answer

Answer: b
Explanation: The DNA is caused to periodically alter its direction of migration by regular changes in the orientation of electric field with respect to the gel.

9. Reorientation angle is difference between ____________
a) Migration direction
b) Field direction
c) Tray direction
d) Gel direction
View Answer

Answer: a
Explanation: The difference between the directions of migration induced by each of the electric fields is the reorientation angle and corresponds to the angle that the DNA must turn as it changes its direction of migration each time the fields are switched.

10. Reorientation angle is the angle of ______________
a) DNA
b) Protein
c) Vector
d) Gel
View Answer

Answer: a
Explanation: The reorientation angle corresponds to the angle that the DNA must turn as it changes its direction of migration each time the fields are switched.

11. Samples do not run in straight lines is a ________ of PFGE.
a) Advantage
b) Disadvantage
c) Cost efficiency
d) Ease
View Answer

Answer: b
Explanation: A major disadvantage of PFGE is that the samples do not run in straight lines, which makes the subsequent analysis of samples difficult.

12. CHEF is a type of _____________
a) Vector
b) Gel
c) Electrophoresis
d) Gene
View Answer

Answer: c
Explanation: The contour-clamped-homogeneous electric field electrophoresis (CHEF) solves the problems encountered in PFGE.
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13. The reorientation angle used for yeast in CHEF is _____
a) 106⁰
b) 110⁰
c) 120⁰
d) 200⁰
View Answer

Answer: a
Explanation: The reorientation angle can be varied in newer CHEF systems and it has been found that for whole yeast chromosomes the migration rate is fastest at 106⁰.

14. DNA fragments of several ________ can be handled using CHEF.
a) Tens
b) Hundreds
c) Thousands
d) Mixed
View Answer

Answer: b
Explanation: DNA as large as 200-300 kb are routinely handled in genomics work and these can be separated in a matter of hours using CHEF.

15. Which reorientation angle is most suited in CHEF for DNA up to several hundred base pairs?
a) 100⁰
b) 90⁰
c) 200⁰
d) 300⁰
View Answer

Answer: b
Explanation: DNA as large as 200-300 kb are routinely handled in genomics work and these can be separated in a matter of hours using CHEF.

Sanfoundry Global Education & Learning Series – Vector Biology & Gene Manipulation.

To practice all areas of Gene Manipulation for Freshers, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn