Micro Exam 2

11-1 Most bacteria reproduce by: sexual reproduction binary fission budding homologous recombination

Binary fission

11-31 Sporulation occurs in: Clostridium Staphylocoocus Klebsiella Citrobacter

Clostridium

10-17 A viral infection is treated with a drug designed to inhibit reverse transcriptase. Which of the following viruses would not be affected? Human Immunodeficiency virus Murine leukemia virus Hepatitis B virus none of these choices

Hepatitis B

11-52 Nonculturable organisms: are rare. can be identified based on their DNA. can only be seen on selective agar plates. have defined generation times.

ID based on their DNA

10-11 Viruses that have plus strand RNA chromosomes that act as a template for DNA synthesis are known as: retroviruses. proviruses. viroids. bacteriophages.

retrovirus

Immune Deficiency Syndrome (AIDS) is caused by a retrovirus. Which of the following best represents the genetic information flow used by retroviruses DNA mRNA protein DNA protein RNA DNA mRNA protein RNA protein

rna, dna , mrna, protein

3-47 The counterstain in the endospore stain is _____. malachite green crystal violet safranin methylene blue

safarin

11-24 Halophiles require an environment with a high concentration of ________ for optimal growth. sugar alcohol salt phosphorous

salt

3-32 Which of the following can be used to examine live specimens? TEM SEM scanning tunneling electron microscope atomic force microscope

scanning tunneling microscope

11-44 Sabourard's agar has a low pH which encourages the growth of molds and discourages the growth of bacteria. Sabourard's agar could best be described as being: selective differential complex enriched

selective

11-45 Bacteria that ferment lactose grow as red colonies on MacConkey's agar while those that do not ferment lactose are transparent. MacConkey's agar can best be described as being: selective differential complex enriched

selective and differential

10-21 Reactivation of chickenpox long after the initial infection leads to: cancer shingels influenza varicella

shingels

3-4 Light of ________ wavelength typically will result in ________ resolution. longer, better shorter, better any, poor shorter, worse

shorter, better

10-42 Recognition of the proper host cell by an animal virus may be aided by the ________ of the virus. spikes tail fibers DNA cell membrane

spikes

11-35 Within a bacterial endospore, the spore is most closely surrounded by the _____. spore membrane cortex cell membrane spore coat

spore membrane

3-40 In a Gram stain, the mordant is _____. crystal violet iodine water alcohol

Iodine

11-47 A living, growing culture whose purpose is to maintain a pure culture of an organism indefinitely is a _____. colony stock culture sporulating culture broth culture

stock culture

10-33 Bacteriophage DNA is transcribed to mRNA during the ________ phase of viral replication. penetration synthesis maturation release

synthesis

10-29 Which of the following is used by (-) sense RNA viruses such as measles and influenza during their replication cycle? synthesize DNA via reverse transcriptase synthesize a double stranded RNA intermediate synthesize an RNA:DNA hybrid whose RNA is a (+) strand synthesize an RNA:DNA hybrid whose DNA is a (-) strand

synthesize a double stranded RNA

10-46 A drug or other agent that induces defects during embryonic development is known as a: syncytia capsomere teratogen carcinogen

teratogen

3-49 What statement about microscopy and staining techniques is false? Many species look identical under the microscope. Staining and microscopic examination are usually all that is need to identify a microorganism. Microscopes are of little use unless the specimens are prepared properly. The degree of contrast is equally important as resolution and magnification.

the degree of contrast is as equally important as resolution and magnification

3-14 During microscopic observation of a specimen, the amount of light that is allowed to pass through the specimen is controlled by the: condenser objective lens iris diaphragm ocular lens

the iris diaphram

3-12 Why is diffraction a problem for microscopy? The lens acts as a large aperture through which light must pass. The small size of higher-power lenses causes severe diffraction. The loss of light results in blurred images Diffraction of light is useful when using an oil immersion lens to view objects.

the loss of light results in a blurred image

3-5 The formula for the resolving power (resolution distance) of a lens is l/2NA (wavelength /2 x numerical aperture). What does this say about resolving power? The smaller the wavelength, the greater the resolving power of the lens. Resolving power is not related to the lens' numerical aperture. We cannot precisely calculate a lens' resolving power. A larger resolving power is indicative of a better lens

the smaller the wavelength the greater the resolving power of the lens

3-1 Which of the following statements about Leeuwenhoek's microscopes is false? Leeuwenhoek kept his technique secret. They magnified objects 100 to 300 times. For each specimen a new microscope had to be made. They were able to reveal very fine details of bacteria.

they were able to reveal fine details of bacteria

3-6 When light passes through an object, ________ of the light has occurred. reflection absorption transmission fluorescence

transmission

3-9 In order to make use of light for a microscopic examination of an object the object must ________ or ________ light. absorb, luminesce transmit, absorb transmit, reflect reflect, absorb

transmit, reflect

3-3 A compound light microscope can generally see objects as no smaller than a _____. ribosome large protozoa small bacterium typical virus

typical virus

3-38 A simple stain: uses only a single dye. requires only one step to stain a slide. distinguishes between two different parts of an organism is composed of an equal balance of acidic and basic dyes.

uses a single dye

3-26 The advent of the electron microscope allowed ________ to be viewed for the first time. protozoa bacteria viruses algae

viruses

10-32 Bacteriophages contain the enzyme lysozyme, which is used to: replicate viral DNA. shut down bacterial cell metabolism. weaken bacterial cell walls. help recognize the proper bacterial host.

weakens bacterial cell wall

11-2 The type of cell reproduction in which a small, new cell develops from the surface of an existing cell and then separates from the parent cell is known as ________ and is the normal mode of replication in _____ . binary fission, bacteria binary fission, yeast budding, bacteria budding, yeast

yeast budding

10-16 The reason that retroviruses can direct the formation of DNA from RNA is because most retroviruses contain the following enzyme RNA polymerase DNA polymerase DNA ligase reverse transcriptase

Reverse transcriptase

Which of the following structures do viruses use to attach themselves and enter the host cells? viral spikes viral tails viral particles viral nucleic acid

Viral spikes

11-26 Which of the following is considered a trace element? carbon zinc sulfur phosphorous

Zinc

10-27 Which of the following represents the correct order of steps in a typical virus replication cycle? maturation , adsorption , penetration , release ,synthesis, adsorption penetration, release, maturation , synthesis adsorption , penetration , synthesis, maturation, release adsorption à penetration à maturation à synthesis à release

absorb penetrate synthesis maturation release

3-8 When light rays pass into an object but do not emerge, ________ has taken place. reflection absorption transmission refraction

absorption

3-44 Which stain would be the best choice for detecting mycobacterium (the bacteria responsible for tuberculosis and leprosy)? simple stain endospore stain acid-fast stain Gram stain

acid fast

11-40 The pour plate method of isolating pure cultures _____. relies on the fact that liquid agar will solidify as it cools is useful for growing microaerophiles results in some organisms growing embedded in the agar all of the above

all of the above

3-35 Atomic force microscope: allows 3 dimensional imaging and measurement of structures as small as nucleotides in DNA is not yet capable of measuring small forces involves ultraviolet light exciting molecules so that they release light of a longer wavelength has a special condenser and objective lens

allows 3D image and measurment of particals as small as nucleotides

3-21 A parfocal microscope: has more than one source of illumination has both coarse and fine focusing adjustment accentuates small differences in the refractive index of intracellular structures allows for specimens to remain in focus when changing between magnification

allows for specimens to remain in focus when changing between magnification

11-51 ______ techniques must be strictly adhered to prevent the accidental contamination of stock cultures. Germination Selective Differential Aseptic

aseptic

10-31 Much of the information about how viruses work has been gleaned from studying T-even phages that infect: bacteria human cells mammalian cells plant cells

bacteria

11-28 Which of the following statements about bacterial growth is false? Agar is used as a solidifying agent in some types of media. Bacteria growing in a liquid culture will generate colonies. A turbid culture is indicative of bacterial growth. Each bacterium plated will represent a colony-forming unit.

bacteria in a liquid culture will generate colonies

10-05 Advantages provided by the viral envelope include: helping viruses infect new cells by fusion of the envelope with the host's plasma membrane. helping viruses "hide" from attack by the host's immune system. resistance to extreme pH (below 6 or above 8). both helping viruses infect new cells by fusion of the envelope with the host's plasma membrane and helping "hide" from attack by the host's immune system.

both a and b

3-22 A microscope in which light rays pass directly through a specimen is a ________ microscope. bright field dark field phase-contrast Nomarski

brightfield

10-45 Enveloped animal viruses typically leave the host cell by: host cell lysis host cell rupture budding animal viruses never leave the host cell

budding

10-25 Select the true statement regarding yellow fever. Yellow fever is endemic to the United States. Yellow fever is only transmitted by one mosquito species Yellow fever is transmitted by ticks and mosquitoes Yellow fever is caused by a flavivirus.

caused by flavivirus

11-8 A bacterial culture can be kept in the log phase of growth indefinitely with the help of a/an: incubator chemostat spectrophotometer colony counter

chemostat

10-20 Which of the following diseases is NOT caused by a poxvirus? smallpox chickenpox cowpox monkeypox

chicken pox

11-42 A growth medium consisting of only water, glucose and beef extract would be considered _____. a defined synthetic medium a complex medium a chemically defined medium two of the above

complex medium

3-18 Most light microscopes contain a/an ________ that converges the light beam so that it passes through the specimen. objective lens iris diaphragm mechanical stage condenser

condenser

11-50 Chocolate agar: contains blood is used exclusively for stock cultures is nutrient poor is a selective agar plate

contains blood

Viruses are referred to as obligate intracellular parasites because viral DNA inserts itself into host DNA. they reproduce and then exit the cell. they use the host's energy to live. they must use the host's machinery to synthesize components required for assembly into new virus particles.

d

11-3 When a bacterial cell divides into two new cells, the new cells are called: daughter cells sister cells son cells father cells

daughter cells

11-48 Which of the following statements about liquid media and agar is false? Both chocolate agar and blood agar contain blood. Stock cultures are never directly used for laboratory studies. A differential media will allow some bacteria to grow and stop the growth of others. A selective media will suppress the growth of some microbes.

differential media allows the growth of some bacteria while inhibiting others

11-43 A media on which Gram-positive organisms turn green and Gram-negative organisms turn blue would be _____. selective differential complex enriched

differentiel

11-10 Which of the following counting techniques does not differentiate between live and dead bacterial cells in a culture? Serial dilution Spread plate Pour plate Direct microscopic count

direct microscopic count

11-5 Which of the following is not one of the phases of bacterial growth? Lag phase Stationary phase Doubling phase Log phase

doubling phase

11-39 The streak plate method produces pure cultures by separating individual bacterial cells from one another by _____. dragging them across a solid surface dispersing them in liquid media killing off those cells that are not able to survive in hot agar embedding some cells in the agar so that they are exposed to lower concentrations of oxygen

dragging them across a solid surface

3-27 Electron microscopes use ________ to focus the electron beam. glass lenses electromagnets mechanical stages laser beams

electromagnets

11-25 Organisms with special nutritional needs are said to be _____. barophiles fastidious aerobes none of these choices

fastidious

3-39 Which of the following is not a differential stain? Gram stain Schaeffer-Fulton acid-fast stain flagellar stain

flagellar stain

3-24 Ultraviolet light is a key component of: bright-field microscopy dark-field microscopy phase-contrast microscopy fluorescence microscopy

fluorescence microscopy

11-49 Microaerophiles: grow best when the environment has a small amount of carbon dioxide. grow best when the environment has a small amount of free oxygen. need a high concentration of carbon dioxide. need a high concentration of oxygen.

grow best with small amount of free oxygen

10-26 In the early 1990's, this emerging virus was of conern to the United States. It is transmitted from rodent feces and urine to human beings. This emerging virus is the: influenza virus rhinovirus hantavirus poliovirus

hantavirus

11-13 Bacterial growth in colonies on agar plates _____. have all phases of growth occurring simultaneously somewhere in the colony most growth occurs at the center of the colony involves budding of small new colonies from the surface of an existing colony have lag phase cells in the center of the colony, surrounded by a ring of cells in exponential phase

have all phases of growth simultaneously

10-19 Which of the following viruses are known for causing latent infections? adenoviruses herpesviruses poxviruses parvoviruses

herpesvirus

Some viruses have a lipid bilayer, also known as the viral envelope. The viral envelope is most likely to come from the following source: host cell plasma membrane host membrane-bound organelles host nucleus another virus

host cell membrane

11-12 Most bacteria: exhibit synchronous growth under natural conditions divide when a small new cell develops from the surface of an existing cell do not immediately increase in number when placed in a culture immediately begin to divide when placed in a culture

immediatly begin to divide when placed in a lab culture

11-1 Microbial growth: refers to the increase in the size of a microbial cell refers to the increase in the frequency of cell division in a single generation time leads to double the cell size in

increase in frequency of cells

10-41 A lysogenic phage which enters a lytic cycle is said to have undergone: transformation induction transcription lysogenic conversion

induction

10-52 A rare form of cancer that was common among men with AIDS is: Kaposi's sarcoma Pneumocystis carinii pneumonia tuberculosis Burkitt's lymphoma

kaposi's sarcoma

10-10 The families of RNA viruses are distinguished from one another by all of the following except: presence of an envelope presence of an envelope sense or antisense RNA whether RNA is linear or circular

linear or circular

11-6 A bacterial population grows most rapidly during ________ phase. lag log stationary death

log

10-40 Growth of a bacterium which contains a prophage represents a: lytic cycle temperate cycle lysogenic cycle induction

lysogenic cycle

10-35 Because viruses such as bacteriophages lead to bursting of the bacterial host cell they are known as ________ viruses. lytic lysogenic recurring lethal

lytic

10-37 Temperate phages: do not always undergo a lytic cycle only replicate at certain temperatures are those that cause disease form plaques on bacterial lawns

lytic cycle

10-28 Assembly of new viral components into a complete virion takes place during viral _____. maturation adsorption penetration synthesis

maturation

11-17 Most human pathogens are _____. psychrophiles mesophiles thermophiles acidophiles

mesophiles

11-46 A candle jar would be used for growing: Gram-negative organisms fastidious organisms thermophiles microaerophiles

microaerophiles

3-37 Which of the following statements about preparing a light microscope specimen is false? Organisms must be heat fixed before being viewed in a hanging drop slide. Smears are loopfuls of medium spread on the surface of a glass slide. Wet mount preparations give good views of microbial mobility. The depth of a smear affects the results; if too thin you may find no organisms.

organisms must be heat fixed before being viewed in a hanging drop slide

3-11 Diffraction occurs when light _____. is reflected by an object passes through a small opening changes wavelengths is absorbed by a normally transparent object (like a glass slide)

passes through a small opening

10-23 A virus that is specific for a bacterial host is called a: phage prion viroid virion

phage

3-23 A microscope that converts changes in the speed of light as it passes through an object into differences in brightness is a ________ microscope. bright field dark field phase-contrast Nomarski

phase contrast

3-25 Which is a false statement about light microscopy? A dark-field microscope produces bright images against a dark background. A phase contrast microscope gives 3-dimensional images. Fluorescent antibody staining cannot determine whether a foreign organism such as a microbe is present in a specimen. A Nomarski microscope produces much higher resolution than the standard phase-contrast microscope.

phase contrast creates a 3D image

3-36 The term "basic dyes" refers to the fact that these dyes are _____. easily prepared positively charged attracted to positively charged cell structures simple in their composition

positively charged

10-01 Viruses have some of the properties of cellular life forms. Which of the following is a characteristic of all organisms except viruses? presence of a plasma membrane capable of mutation ability to reproduce inside a living host grow in response to their environmental conditions

presence of a plasma membrane

10-9 DNA viruses are grouped into families based on the following characteristics except: presence of an envelope presence of a capsid whether DNA is single stranded or double stranded whether DNA is linear or circular

presence of capsid

10-44 Cells taken directly from an animal and cultured in vitro represent: primary cell cultures continuous cell lines from human embryos continuous cell lines that have been re-isolated from animal tissues

primary cell culture

10-49 Diseases such as Creutzfeld-Jacob disease (variant), kuru, and mad cow disease are caused by: RNA viruses DNA viruses bacteria prions

prions

10-38 Viral DNA lying within a bacterial chromosome is called a ________ while the combination of a bacterial cell and its temperate phage is called a ________. prophage, lysogen plaque, lysogen lysogen, prophage prophage, retrovirus

prophage, lysogen

11-32 Endospores are: metabolically active reproductive structures found mostly in Gram negative organisms protective structures

protective structures

10-48A prion is composed of: RNA DNA protein both DNA and RNA

protein

3-41 In a properly executed Gram stain, Gram positive organisms appear ________ while Gram negative organisms appear ________. pink, clear pink, purple purple, pink purple, blue

purple,pink

3-7 When light bends as it passes through an object, ________ of the light has occurred. reflection absorption transmission refraction

refraction

11-15 Acidophiles would be expected to grow best at a pH of _____. 3 6 9 12

3

3-19 The total magnification of a specimen being viewed with a 10X ocular lens and a 40X objective lens is _____. 4X 40X 400X 4000X

400X

10-12 You have isolated an unknown virus. It is a double-stranded DNA virus and does not have an envelope. To which virus family does it mostly likely belong? Paramyxoviridae Retroviridae Adenoviridae Parvoviridae

Adenoviridae

3-43 If the step involving iodine were left out of a Gram stain, which of the following would best describe the results? Gram negative cells would look Gram positive. Gram positive cells would look Gram negative. All rods would be pink, all cocci purple. All cells would be purple.

All cells would be purple

3-50 When given a microorganism to identify, which of the following would be useful? A Gram stain A transmission electron micrograph Biochemical and genetic characteristics All of the above

All of the above

3-30 Electron microscopes: that are scanning have better resolution than those that are transmission are much more expensive and take up more space than light microscopes can use the same preparations of specimens that have been prepared for viewing with a light microscope have a resolving power approximately 10 times better than the best light microscope

Are much more expensive and take up more space

10-14 All of the following viruses may stay inside of a cell for many years and remain inactive except: herpes simplex chickenpox HIV enterovirus

Enterovirus

10-18 A latent viral infection is an infection in which: viral replication is slow viruses remain within host cells without ever causing a disease a viral infection causes a disease progression gradually over a long period viral replication has stopped but may resume years or decades later upon reactivation

B or D

3-42 Why do basic dyes attach to most bacterial surfaces? Most bacterial surfaces are negatively charged. Bacterial cells take up safranin. Most bacterial surfaces resist taking up the stain. Most bacterial surfaces do not have a charge.

Bacterial surfaces are negatively charged

11-41 A growth medium consisting of only known amounts of water, magnesium, calcium chloride, potassium and glucose would be considered: a defined synthetic medium a complex medium a chemically nondefined medium two of the above

Defined synthetic medium

11-19 Which type of cell will generally shift to aerobic metabolism when oxygen is available but will carry on fermentation otherwise? aerotolerant anaerobes facultative anaerobes obligate anaerobes obligate aerobes

Facilitated anaerobes

11-18 Which of the following is most likely to have evolved to live in the deep layers of mud, where there is a complete lack of free oxygen? Obligate aerobe Obligate anaerobe Facultative anaerobe Aerotolerant anaerobe

Obligate anerobes

11-38 A culture that contains only a single species of organism is known as a _____. pure culture Koch culture mixed culture contaminated culture

Pure culture

3-16 A compound microscope has _____. two eyepieces a total magnification of 5,000X only fine adjustment and no coarse adjustment more than one lens

more than one lens

11-11 Which of the following bacterial counting techniques relies on a statistical estimate to determine the number of bacteria in a culture? Serial dilution Standard plate count Spread plate Most probable number

most probable number

3-48 Bacterial capsules can best be visualized by _______ staining flagellar crystal violet negative mordant

negative

3-46 Which type of staining results in a clear object being viewed against a dark background? Simple stain Negative stain Endospore stain Flagellar stain

negative staining

11-7 In the stationary phase of bacterial growth: the number of newly generated cells is greater than the number of dying cells the number of newly generated cells is less than the number of dying cells the number of newly generated cells is the same as the number of dying cells none of the above

newly generated cells equals the same number as dying

A naked virus: has no protein coat around its nucleic acid. is unable to attach itself to a host cell. has no envelope has no infectious piece of DNA

no envelope

10-22 Viral host range refers to the: tissue types able to be infected by a virus number of species that are infected by a virus number of eukaryotic kingdoms able to be infected by a virus none of these choices

number of species

3-15 The lens closest to the slide during a microscopic examination is the _____. ocular objective condenser compound

objective

3-20 To calculate the total magnification of a light microscope you must know the magnification of the _____ lenses. objective and condenser ocular and condenser objective and condenser objective and ocular

objective and occular

11-9 Serial dilutions are used to slow down the growth of microbes speed up the growth of microbes obtain bacterial cultures at several different concentrations form bacterial colonies

obtain bacterial cultures at several different concentrations

3-17 The lens closest to your eyes during a microscopic examination is the _____. ocular objective condenser compound

occular