Microbiology Exam 1 Test Questions

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True or False:

Archaea contain peptidoglycan in their cell walls.

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False
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Which microorganism class are extreme halophiles and extreme thermophiles.
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Archaea
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True or False:

Fungi are prokaryotes

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False

Eukaryotes

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True or False:

Yeasts are unicellular fungi

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True
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What type of motility does a sporozoan have?
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No motility
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Amoebae move via what method of motility?
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Pseudopods
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Photosynthetic eukaryotes are also known as _______?
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Algae
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Who proposed the cell theory?
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Robert Hooke
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Who discovered microorganisms?
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Anton van Leeuwenhoek
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Who disproved the theory of spontaneous generation
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Pasteur and Tyndall
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Who developed the vaccine for anthrax? Rabies?
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Louis Pasteur
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Who proposed aseptic technique?
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Louis Pasteur
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True or False:

Louis Pasteur proposed the germ theory

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True
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What scientist(s) was/were credited for discovering fermentation?
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Louis Pasteur
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Who is known as the father of antiseptic surgery?
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Lister
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True or False:

Lister was known for using carbolic acid.

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true
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Who postulated the germ theory?
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Koch
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Who identified the microbes which caused anthrax rabies etc?
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Koch
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What scientist created micro. media and streak plates?
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Koch
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Who discovered penicillin>
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Alexander fleming
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What term means to measure the relative velocity of light passing through an objective?
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Refractive index
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Basic dyes have what charged ion? Acidic ions? Purpose of each.
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Basic – positive – stains bacteria
Acidic – negative – stains background
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What are the functions of granules in a bacterial cell?
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To hold nutrients
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What cell structure in bacteria helps adhesion to various other substances?
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Fimbraie
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Function of pilus/
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Transfer DNA to other cells
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Axial filament function?
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locomotion
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What is the virulence factor and what is it composed of?
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prevents phagocytosis but enhancing adhesion

Made up of sugars

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What composes the cell envelope?
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Anything external to the cytoplasm
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True or False:

Gram + bacteria have a thinner peptidoglycan layer than gram –

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False
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True or False:

Techoic acids are part of the peptidoglycan layer

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true
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What is the function of techoic acids?
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to prevent cell wall breakdown
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True or False:

Only gram positive bacteria contain a periplasmic space

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False

Only gram negative does

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True or False:

Both gram positive and gram negative bacteria contain porins.

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False

Only gram negative

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Why is mycoplasma considered to be an atypical cell wall
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No cell wall (Only sterol membrane)
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Why is mycobacterium considered atypical?
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It contains mycolic acids in the cell wall
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Where does ATP production occur at in a bacterial cell?
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Plasma membrane
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What is group translocation and describe its locomotion?
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Group translocation describes a mode of active transport that requires PEP. It chemically alters the transported material during transport
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What % of the cytoplasm is water/
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80 percent
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True or False:

If a bacterial cell does not contain a plasmid, it cannot survive.

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false

plasmids are typically not required to survive

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Describe the morphology of a bacterial cell dna?
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Small, circular, dsDNA
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What is the size of the ribosomal subunits for prokaryotes and what is the total size?
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70s with 50s and 30s subunits
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What is a vibros cell shaped like?
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Half circle, bacilli
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What is the ribosome size and subunit size of a eukaryotic cell?
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80s with 60s and 40s subunits
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Via the Embden Meyerhoff pathway, what does glucose produce?
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2 pyruvate, 2 atp, 2 nadh
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Via fermentation, how many atp molecules can be produced by one glucose molecule
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2
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What is the main source of carbon for photoautotrophs?
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CO2
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What is the main source of carbon for photoheterotrophs?
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Organic compounds
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Chemoautotrophs use ___________ as the chief source for energy? Use ___________ as principle carbon source.
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electrons from reduced inorganic compounds

CO2

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Chemoherterotrophs use _____________ as the main source of energy? Use _________ as principle carbon source.
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hydrogen ions from organic compounds

carbon comes from same source as energy

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True or false:

Bacteria, fungi, and animals are considered chemoautotrophs.

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False:

They are chemoheterotrophs

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What is an amphibolic pathwya?
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One that does anabolic and catabolic functions
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Optimal environment for a psychrophile?
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Below 15 deg. C
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Optimal environment for a mesophile?
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20 – 40 deg. C
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Optimal environment for a thermophile?
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Above 45 deg. C
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Optimal environment for a halophile?
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Salt concentration above 2%
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What 4 elements are needed for bacterial cell growth? What other 2 factors are needed?
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Carbon, nitrogen, sulfer, phosphorus

Trace elements (cofactors)
Organic growth factors (vitamins)

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What is another name for a capnophile
optimal environment?
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Microaerophile

Lower O2 [ ] and higher CO2 [ ] than present in atmosphere

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Function of superoxide dismuatse?
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Get rid of O2 radical
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Function of catalase?
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Break down H2O2 into H20 and O2
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True or False:

An oxidizing medium is required for an anaerobe culture.

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False

A reducing medium

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Function of pallidium in anaerobic chamber?
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Gets rid of O2
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Function of a selective medium?
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Suppress unwanted bacterial growth
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Blood agar is what type of medium? MacConkey agar? Mannitol Salt agar?
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Blood agar – differential

MacConkey – differential and selective

Mannitol salt – selective

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Disinfectant vs antiseptic
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disinfected – used on inert substances
antiseptic – used on living tissue
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Time in min. required to know thermal death point?
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10 min
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What is the decimal reduction time?
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time in min. that it takes to kill 90 percent of bacteria
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How does moist heat kill?
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Breaking H-bonds and coagulating proteins
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How long does it take an autoclave to kill pathogens?
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15 mins
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describe HTST?
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72 deg C for 15 sec
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How does ionizing radiation work? (h20)
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By forming highly reactive hydroyl radicals
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Chemically defined synthetic medium?
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Exact chemical structure is known for every substance
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Complex medium?
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Atleast 1 exact structure is unknown
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How do UV rays kill and cause mutations?
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Formation of thymine dimers
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How do phenol and its derivatives kill?
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Injures plasma membrane, inhibits enzymes and protein function
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What is the number one disinfectant here at ruby? How does it work?
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Hibiclens

Works by damaging plasma membrane (not sporicidal)

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What is the second rated surgical scrub? How does it work?
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Betadine

Works by oxidizing SH groups of pathgens by combining with tyrosine

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Hypochlorous acid aka _______?
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Bleach
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How do heavy metals disinfect?
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By combining with SH groups
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Surfactants disinfect by ____________?
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Mechanical methods (scrubbing)
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True or False:

Quaternary Ammonia Compounds are anionic.

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False

Cationic

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True or False:

Quaternary Ammonia Compounds work better on gram – positive rather than gram – negative.

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true
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Cepacol and Zephiran are what type of disinfectants?
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Quaternary Ammonia Compounds
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How does formaldehyde work as a disinfectant?
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Forms covalent cross-links with organic compounds
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What type of disinfectant is ethylene oxide and how does it work?
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Gaseous Chemosterilizer

Works by denaturing proteins

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True or False:

H2O2 is a good disinfectant for open wounds.

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True

By NOT a good antiseptic

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True or False:

Constituitive enzymes are produced only when needed

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false

they are constantly produced

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How does a repressor work?
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Represses the ability of RNA pol. to initiate transcription
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What are inducible enzymes?
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enzymes synthesized in the presence of an enzyme
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What region of a lac operon codes for the repressor?
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I region
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What molecule binds to the lac operon to initiate transcription?
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RNA pol.
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A lac operon repressor will bind to which region?
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O region
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What lactose and glucose are present, the lac operon is _____________.
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Repressed
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How are genes transferred between bacteria? (form, not method)
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As naked DNA
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What form must the genetic material be in for bacterial conjugation to occur?
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Plasmid form
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True or False:

Conjugating cells must be opposite type?

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true
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True or False:

Bacterial conjugation occurs by direct cell-to-cell contact

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true
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An F+ cell is described as? F- Cell?
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F + donor cell with plasmid

F – donor cell without plasmid

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How does an HFr cell occur?
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If the F factor of one cell moves into the chromosome of a cell without an F factor
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Lysogenic is described as…
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incorporating dna into bacterial chromosome
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True or False:

Bacterial transduction involves a bacteriophage (bacterial virus)

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true
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What is another name for transposable genes?
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jumping sequences
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during recombinant gene formation, what role does reverse transcriptase play with mRNA?
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it digests mRNA
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What produces DNA from an mRNA template?
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reverse transcriptase

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