Culture, Nutrition and Sterilization Methods - Methods in Microbiology - Life Sciences Previous Year Questions

1

2007 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2007

Infection of E.coli by bacteriophage λ is normally detected by

A

Resistance of the bacteria to an antibiotic

B

Growth of single colony on the agar plate

C

The appearance of plaques or lysed bacteria on agar plates

D

Restriction digest of the bacterial DNA

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2

2007 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2007

MacConkey agar is a type of

A

Selective media

B

Differential media

C

Both selective & differential media

D

None of these

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3

2007 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2007

Calculate the efficiency of this transformation in CFU/μg of DNA

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4

2009 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2009

Baculovirus expression system is used to express heterologous genes in

A

Mammals

B

Plants

C

Insects

D

Yeasts

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5

2010 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2010

Wild type E.coli forms purple colored colonies on EMB-lactose plate. This is due to

A

increase in pH of the medium

B

decrease in pH of the medium

C

secretion of purple colored pigment

D

secretion of β-galactosidase

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6

2010 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2010

The quickest way to determine bacterial growth in terms of viable cells is through

A

Most probable number (MPN) technique

B

Spread plate method

C

Pour plate method

D

Slide culture technique

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7

2010 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2010

A bacterial culture was diluted 1000 fold and 0.1 ml of this diluted sample was spread per plate on nutrient agar. In a triplicate run, the number of colonies formed is 121, 93 and 86. The number of colony forming units/ml in the original bacterial culture is

A

10⁶

B

10⁵

C

10⁴

D

10²

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8

2012 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2012

An auxotrophic mutant arises spontaneously in a wild type E.coli culture growing in a rich medium. Which ONE of the following techniques will ensure the isolation of the auxotrophic mutant?

A

Replica plating

B

Streaking for single colonies

C

Pour plating method

D

Direct microscopic observation

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9

2013 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2013

In a population containing fast and slow growing bacteria, the slow growing bacteria can be enriched by supplementing the medium with

A

chloramphenicol

B

penicillin

C

penicillin & chloramphenicol

D

rifampin

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10

2013 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2013

In a phenol coefficient test for determining the efficacy of a disinfectant X, the maximum effective dilution for X and phenol was found to be 1/450 and 1/90, respectively. Calculate the phenol coefficient for X.

A

10.0

B

5.0

C

1.0

D

0.2

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11

2014 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2014

Match the media in Group I for screening microbial isolates in Group II.

Group I
(P) Blood agar media
(Q) Minimal media
(R) Skimmed milk agar media
(S) Bile salt media

Group II
(i) Coliforms
(ii) Protease producers
(iii) Hemolytic microbes
(iv) Lipase producers
(v) Autotrophs

A

P-iii, Q-v, R-ii, S-i

B

P-iii, Q-ii, R-i, S-iv

C

P-i, Q-iii, R-ii, S-iv

D

P-ii, Q-i, R-iv, S-v

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12

2014 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2014

Match items in Group I with sterilization methods in Group II.

Group I
(P) Ampicillin
(Q) 1% glucose in phosphate buffer
(R) Plastic syringe
(S) Luria broth

Group II
(i) 70 % alcohol treatment
(ii) Autoclaving at 15 psi for 15 min
(iii) Autoclaving at 10 psi for 20 min
(iv) Membrane filtration
(v) γ-ray irradiation

A

P-iv, Q-iii, R-v, S-ii

B

P-iii, Q-iv, R-ii, S-v

C

P-i, Q-ii, R-v, S-iii

D

P-v, Q-ii, R-iii, S-i

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13

2015 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2015

Of the following, the most effective method to kill bacterial endospores is

A

moist heat sterilization

B

UV irradiation

C

filtration

D

pasteurization

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14

2017 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2017

Which one of the following statements is TRUE about MacConkey (MAC) agar medium?

A

MAC agar medium is a selective and differential medium for Gram-positive bacteria.

B

MAC agar medium is a selective and differential medium for Gram-negative bacteria.

C

MAC agar medium is an enriched medium for Gram-positive bacteria.

D

MAC agar medium is a synthetic medium for Gram-positive and Gram-negative bacteria.

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15

2017 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2017

One-ml sample of a bacterial culture was serially diluted to \(10^5\) times, and 46 colonies were obtained after plating this diluted sample on an agar medium. The number of cells present per ml in the undiluted original sample were ________

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16

2017 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2017

The transformation efficiency of competent cells prepared in a laboratory is \(10^4\) CFU/μg of plasmid DNA. If 0.01 μg of this plasmid is used to transform these competent cells, the number of transformed bacteria in CFU after plating will be ________

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17

2017 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2017

In dye-reduction test for estimation of viable microorganisms, the most commonly used dyes are methylene blue, triphenyltetrazolium–chloride and ______ .

A

Malachite green

B

Amaranth

C

Tartrazine

D

Resazurin

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18

2020 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2020

An example of a differential and selective medium in which colonies of Gram-negative bacteria produce large amounts of acidic products and appear green with a metallic sheen is

A

Blood agar

B

EMB agar

C

MacConkey agar

D

Mannitol salt agar

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19

2020 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2020

A 100 μl aliquot (\(10^{-4}\) dilution) of the bacterial culture plated on the nutrient agar gave 4 colonies. The bacterial stock concentration (in million cells/ml, rounded off to one decimal place) is ____.

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20

2024 · Life Sciences · Methods in Microbiology · Culture, Nutrition and Sterilization Methods

Life Sciences (XL) 2024

In which of following processes, glutaraldehyde is used as a sterilizing agent?

A

Pasteurization

B

Incineration

C

Cold sterilization

D

Autoclaving

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