Buffers, Separation and Electrophoresis - Analytical Techniques - Life Sciences Previous Year Questions

1

2007 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2007

When yeast cells are shifted from a medium containing glycerol to glucose, an increase in the transcription of four genes involved in glucose metabolism was reported. Which of the following would be the most appropriate technique to demonstrate increased transcription of these genes?

A

Southern hybridization

B

Northern hybridization

C

Western hybridization

D

Fluorescence in situ hybridization

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2

2007 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2007

A mixture containing protein-1, -2, -3, -4, and -5 with molecular weights 5,000, 10,000, 25,000, 65,000, and 100,000, respectively, were separated on a Sephadex G-50 column. The order of elution of these proteins from the column will be

A

Protein-1, protein-2, protein-3, protein-4, and protein-5

B

Protein-5, protein-4, protein-3, protein-2, and protein-1

C

Protein-1, -2, and -3 elute first, followed by protein-5 and -4

D

Protein-4 and -5 elute first, followed by protein-3, -2, and -1

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3

2007 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2007

Protein binding regions of DNA are identified by one of the following techniques

A

finger printing

B

foot printing

C

southern blotting

D

western blotting

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4

2007 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2007

A protein binds to phosphocellulose column at pH 7.0 and elutes at pH 8.0. If the protein has to be further purified on a DEAE Sephacel column, the binding buffer should have a pH of

A

5

B

6

C

7

D

8

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5

2007 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2007

If 10³ cells survived after electroporation, how many cells were killed during this process (round of to the nearest number) ?

A

10⁹

B

10⁸

C

10⁶

D

10⁵

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6

2008 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2008

A mixture of proteins namely P, Q, R and S having molecular mass 50, 80, 120, and 150 KDa is applied on the Sephadex- G 200 column. The order of their elution will be

A

P, Q, R, S

B

S, R, Q, P

C

Q, P, R, S

D

P, Q, S, R

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7

2008 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2008

Which of the following techniques is best suited for immobilizing an affinity ligand?

A

Physical adsorption

B

Gel entrapment

C

Cross-linking with a polymer

D

Covalent linkage to a spacer arm

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8

2008 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2008

A DNA fragment of 4500 bp has to be tailed with dT residues by using dTTP and the enzyme ‘terminal transferase’. The stock solution of dTTP that is used as a substrate has a concentration of 150 μM. Ten μl of this stock solution is added to a total volume of 200 μl reaction. What will be the concentration of dTTP in the reaction?

A

7.5 μM

B

75 μM

C

0.75 μM

D

0.075 μM

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9

2008 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2008

Match the coefficients in group 1 with their corresponding downstream processing steps given in group 2

Group 1	Group 2
(P) Sedimentation coefficient	1. Aqueous two-phase extraction
(Q) Partition coefficient	2. Ultrafiltration
(R) Rejection coefficient	3. Dialysis
(S) Activity coefficient	4. Centrifugation

A

P-3, Q-1, R-4, S-2

B

P-2, Q-1, R-4, S-3

C

P-4, Q-3, R-1, S-2

D

P-4, Q-1, R-2, S-3

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10

2008 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2008

After completion of Nick translation reaction, 10 μl of reaction was spotted on a glass-fibre filter that upon counting resulted into 4.2 x 10⁴ cpm in reaction. Another 10 μl was processed for TCA precipitation to determine radioisotope incorporation. The TCA precipitated sample gave 2.94 x 10⁴ cpm. What is the percent of [α-³²P]-dCTP incorporation into the DNA sample?

A

40%

B

50%

C

60%

D

70%

Check answer

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11

2009 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2009

IgG has four chains. Purified monoclonal IgG was subjected to electrophoresis. The number of bands visible by
a) Reducing SDS-PAGE     b) Isoelectric focusing     c) Native PAGE
are

A

2; b-1; c-1

B

1; b-1; c-2

C

2; b-4; c-2

D

4; b-2; c-4

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12

2009 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2009

A mixture of amino acids consisting of glycine, lysine, arginine, histidine, aspartic acid and glutamic acid was placed in the centre of a paper strip, moistened with buffer of pH 6 and electric current applied. The migration of amino acids was as follows:

A

Glycine, lysine and histidine moved towards the anode. Aspartic acid and glutamic acid moved towards the cathode while arginine remained near the origin.

B

Aspartic acid and glutamic acid remained near the origin and lysine, histidine and glycine moved towards the anode while arginine moved towards the cathode.

C

Glycine remained near the origin. Lysine, arginine and histidine moved towards the cathode while aspartic acid and glutamic acid moved towards the anode.

D

All amino acids remained near the origin.

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13

2009 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2009

Group I	Group II
P. [DNA sequence]	1. EcoRI
Q. [DNA sequence]	2. AluI
R. [DNA sequence]	3. HpaII
S. [DNA sequence]	4. HindIII
	5. PstI
	6. HincII

A

P-1, Q-5, R-6, S-3

B

P-2, Q-6, R-3, S-4

C

P-1, Q-6, R-4, S-2

D

P-1, Q-2, R-6, S-4

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14

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

Which of the following options is the closest in meaning to the word below:
Circuitous

A

cyclic

B

indirect

C

confusing

D

crooked

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15

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

25 persons are in a room. 15 of them play hockey, 17 of them play football and 10 of them play both hockey and football. Then the number of persons playing neither hockey nor football is:

A

2

B

17

C

13

D

3

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16

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

5 skilled workers can build a wall in 20 days; 8 semi-skilled workers can build a wall in 25 days; 10 unskilled workers can build a wall in 30 days. If a team has 2 skilled, 6 semi-skilled and 5 unskilled workers, how long will it take to build the wall?

A

20 days

B

18 days

C

16 days

D

15 days

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17

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

Hari (H), Gita (G), Irfan (I) and Saira (S) are siblings (i.e. brothers and sisters). All were born on 1st January. The age difference between any two successive siblings (that is born one after another) is less than 3 years. Given the following facts:
i. Hari's age + Gita's age > Irfan's age + Saira's age.
ii. The age difference between Gita and Saira is 1 year. However, Gita is not the oldest and Saira is not the youngest.
iii. There are no twins.
In what order were they born (oldest first)?

A

HSIG

B

SGHI

C

IGSH

D

IHSG

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18

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

A mixture of proteins (W, X, Y, Z) elute from Sephades G-200 column in the order W, X, Y, Z. The protein with maximum electrophoretic mobility on SDS-PAGE will be

A

W

B

X

C

Y

D

Z

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19

2010 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2010

Match the items in Group 1 with the most appropriate separation techniques in Group 2 Group 1: P. Mixture of glycine and albumin, Q. Mixture of 20 and 60 kDa proteins, R. Histones from nuclear extract, S. Lectins Group 2: 1. Gas chromatography, 2. Dialysis, 3. Affinity chromatography, 4. Size exclusion chromatography, 5. Thin layer chromatography, 6. Cation exchange chromatography

A

P-1, Q-4, R-3, S-5

B

P-5, Q-3, R-6, S-1

C

P-2, Q-4, R-6, S-3

D

P-6, Q-5, R-2, S-4

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20

2011 · Life Sciences · Analytical Techniques · Buffers, Separation and Electrophoresis

Life Sciences (XL) 2011

The question below consists of a pair of related words followed by four pairs of words. Select the pair that best expresses the relation in the original pair.
Gladiator : Arena

A

dancer : stage

B

commuter : train

C

teacher : classroom

D

lawyer : courtroom

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