MicroBiology MCQs Chapter 3

The Petroff­Hausser counting chamber consist of ________.

A. 25 squares
B. 100 squares
C. 50 squares
D. none of the above

ANSWER: A


A culture containing only one kind of microorganism is called ________.

A. synchronous culture
B. pure culture
C. auxenic culture
D. continuous culture

ANSWER: B


The process that reduces the bacterial count to safe levels as may judged by the public health is referred as ________.

A. sterilization

B. sanitization

C. disinfection

D. antisepsis
ANSWER: B


Culture containing more than one kind of microorganism is called ________.

A. synchronous culture

B. pure culture
C. auxenic culture
D. continuous culture

ANSWER: C


To maintain the bacterial population in ______ phase is referred as continuous culture.

A. lag phase
B. log phase
C. stationary phase
D. death phase

ANSWER: B


Slide culture technique is used for ________ cultivation

A. bacterial
B. fungi
C. virus
D. algae

ANSWER: B


The type of media is used for fungi cultivation is ________ agar.

A. nutrient
B. Mac Conkeys
C. sabourauds
D. plant

ANSWER: C


Macintosh Jar is used for ________.

A. cultivation of anaerobes
B. cultivation of aerobes
C. fungal cultivation
D. algal cultivation

ANSWER: A


Maintenance of sterile condition is referred as ________.

A. aseptic technique
B. septic technique
C. disinfection
D. fumigation

ANSWER: A


 _______ rays are referred as non ionizing radiations.

A. UV
B. X
C. gamma

D. cathode
ANSWER: B


In Laminar air flow_________ type of filter is located

A. membrane filter
B. seitz filter
C. HEPA
D. slow filter

ANSWER: C


___________ is referred as biological indicator of autoclave.

A. Bacillus stearothermophilus
B. Bacillus subtilis
C. Bacillus megatorium
D. Bacillus cereus

ANSWER: A


Fluorescent substance is used in ________.

A. viscometer
B. centrifugation
C. flow cytometry
D. spectrophotometer

ANSWER: D


The process of killing or removal of organisms capable of causing infection is called as ______.

A. sterilization

B. sanitization

C. disinfection

D. antisepsis
ANSWER: A


The pH meter standardized with pH ________.

A. 7
B. 2

C. 14

D. 4
ANSWER: A


Colorimeter is applied only in relation to _______.

A. uv light
B. X rays
C. visible light
D. IR rays

ANSWER: A


The amount of light absorbed by a material is proportional to the concentration of the absorbing solution is referred as ________ law.

A. Beers
B. Bogers Lambert

C. Poiseuilles
D. Newtons
ANSWER: A


Separation of small molecule can be done by ________.

A. viscometer
B. centrifugation
C. flow cytometry
D. spectrophotometer

ANSWER: B


Microbes such as E. coli are able to manufacture vitamin in the human intestinal tract _____.­ 

A. A

B. D

C. C

D. K
ANSWER: D


A slippery outer covering in some bacteria that protects them from phagocytosis by host cells is ________.

A. capsule
B. cell wall
C. flagellum
D. peptidoglycan
ANSWER: A


Gram negative cell wall is __________ than a Gram positive one.

A. thicker
B. thinner
C. thickest
D. thin

ANSWER: B


Most human pathogens prefer temperatures near that of the human body. They are called as

A. psychrophiles
B. thermophiles
C. mesophiles
D. halophiles

ANSWER: C


Which year Beijerinck found the free living nitrogen fixing bacteria Azotobacter __________.

A. 1909
B. 1919

C. 1921

D. 1901
ANSWER: D


_______ are very small, multi­shaped bacteria lacking a true cell.

A. Rickettsias
B. Actinomycetes
C. Spirochetes
D. Mycoplasmas

ANSWER: A


Magnetite­bearing magnetosomes have also been found in eukaryotic magnetotactic _________.

A. algae
B. fungi
C. bacteria

D. protozoan
ANSWER: A


The model organism, which used to study endospore formation is ________.

A. Bacillus subtilis
B. Escherichia coli
C. Streptomyces aureus

D. yeast

ANSWER: A


The role of pili in cloning of bacteria in E.coli is ________.

A. conjugation
B. transformation
C. tranfection
D. transduction

ANSWER: A


Some pathogenic bacteria develop resistance to antibiotics by ________.

A. modifying their cell walls

B. developing such enzymes which modify antibiotics
C. alter the antibiotics target due to spontaneous mutation
D. all the above

ANSWER: D


A biofertiliser is ________.

A. living
B. nonliving

C. chemical

D. synthetic
ANSWER: A


Cyanobacteria helps farmers by ________.

A. reducing the alkalinity of the soil
B. reducing the acidity of the soil
C. neutralising the alkalinity of the soil
D. water logging

ANSWER: B


Various commercial products of economic value made by microbes are ______

A. medicines
B. organic acids
C. amino acids
D. all the above

ANSWER: D


Many individuals of the same species living together in a defined area form a/an ________.

A. community
B. genus
C. population
D. ecosystem

ANSWER: A


Why is it difficult to integrate nitrogen gas from the atmosphere into the nitrogen cycle of the biosphere

A. nitrogen is not very abundent in the atmosphere
B. few organisms can directly utilize atmospheric nitrogen gas
C. most plants do not require organic nitrogen compounds for survival

D. oceans quickly absorb nitrogen gas
ANSWER: B


A culture medium on which only Gram positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called a ________.

A. selective medium

B. differential medium
C. enrichment culture
D. a and b

ANSWER: D


Abiogenesis refers to the ________.

A. spontaneous generation of organisms from nonliving matter

B. development of life forms from preexisting life forms
C. developmeat of aseptic technique
D. germ theory of disease
ANSWER: A


While using any pair of carbon compounds as long as other nutrients are not limiting, the bacteria shows ______ growth.

A. diauxic
B. continuous

C. batch
D. synchronous
ANSWER: A


Endospores were first discovered by ________.

A. Ferdinand Cohn
B. Louis Pasteur
C. John Tyndal
D. Anton von Leeuwenhoek

ANSWER: A


The protein surrounded the genetic material of viruses are called ________.

A. envelope
B. capsid
C. cover
D. cortex

ANSWER: B


Bacterial ribosomes are composed of ________.

A. protein and DNA
B. protein and rrna
C. protein and mrna
D. protein and RNA

ANSWER: B


Energy production in anaerobes is not by ________.

A. TCA cycle
B. EMP pathway
C. fermentation
D. pentose phosphate shunt

ANSWER: A


Contagious disease spreads by ________.

A. inhalation
B. ingestion
C. inculation

D. contact

ANSWER: D


The widely used fumigant is ________.

A. ethylene
B. chlorine
C. formaldehyde
D. CO2

ANSWER: C


Lyophilization is a method of ________.

A. characterization of microorganisms
B. destroying microorganisms
C. preservation of microorganisms
D. regulating microorganisms ANSWER: C


________ fungi shows sexual reproduction

A. aPathogenic
B. Reproductive
C. Perfect
D. Saprophytic.

ANSWER: C


The first virus to be crystallized was ________.

A. rabies
B. pox virus
C. tobacco mosaic virus

D. polio virus
ANSWER: C


The iodine­organic carrier complex iodophore is __________.

A. ethylene oxide
B. methane
C. chloroform
D. ozone

ANSWER: A


In nitrogen fixation, nitrogen from the atmosphere is combined with __________.

A. oxygen atoms
B. hydrogen atoms
C. carbon atoms
D. calcium atoms

ANSWER: B


An example of a non­ionizing type of radiation which is microbiocidal is ________.

A. gamma rays
B. uv rays
C. X­rays
D. electrons

ANSWER: C


The principle behind the sterilization using autoclave is ________.

A. high pressure

B. bhigh steam
C. hot vapors
D. steam under pressure
ANSWER: D


Microbe is bright and the field is dark in_________.

A. dark­field microscopy
B. phase contrast microscopy
C. bright field microscopy
D. electron microscopy

ANSWER: A

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