Microbiology Test 1 chapter 3
The prokaryotic ribosome is a ________S ribosome
70
The density of the ribosome in a prokaryote is:
70S
Which staining technique allows differentiation of mycobacterial cells?
Acid fast stain
Which of the following are functions of the glycocalyx?
Adherence and protection
Members of the Domain ______ have peptidoglycan in their cell walls, whereas members of the Domain ________ have unique cell wall composition.
Bacteria ; Archaea
Put the following in order with the group containing the most organisms at the top. Strain Species
Species Strain
______ possess wound DNA enclosed in a nucleus and membrane bound organelles whereas _______ cells do not encase their DNA or organelles in a membrane
Eukaryotes ; prokaryotic
True or False: The gram negative cell wall has more peptidoglycan than the gram positive cell wall
False
True or False: The gram-negative cell wall has more peptidoglycan than the gram-positive cell wall.
False
The ____ stain techniques allows a microbiologist to differentiate bacteria based on their cell wall composition/structure
Gram
The discoverer of a staining technique for the differentiation of bacteria based on their cell walls was named Hans Christian ______
Gram
Which type of cell walls are thicker?
Gram positive
______ are able to flourish at high temperatures such as those found in thermal heat vents and volcanic waters
Hyperthermophiles
Bacteria that lose their cell wall during some point in their life cycle are known as __________ __________.
L - forms
When a bacterial cell loses its cell wall it is known as a(n):
L form
When a bacterial cell loses its cell wall, it is known as a(n):
L form
Which of the following are types of flagellar arrangements with more than one flagellum?
Peritrichous, Amphitrichous, Lophotrichous
Which of the following describes cocci in irregular clusters?
Staphylococci
Gram negative bacteria are the only type of bacteria that have been found to possess which external appendage?
Pilus
The hollow tubular appendage on a capsule is a?
Pilus
What term distinguishes between different bacteria based on the immunological response they elicit in a host?
Serotype
The following describes cocci in chains?
Streptococci
What is the difference between a true nucleus and a nucleoid?
a true nucleus is surrounded by a membrane whereas a nucleoid is not
The ______ - _______ stain technique would be used to discover Mycobacterium tuberculosis in a sputum sample.
acid - fast
The two main functions of the glycocalyx are _____ and ______
adherence, protection
A cell membrane, ribosomes, chromosome(s) and cytoplasm are found in _______ bacterial cells.
all
Which is true regarding all prokaryotes?
all lack a nucleus
The glycocalyx is important in the ability of bacteria to cause infection because it can?
allows for the formation of biofilms, helps the bacteria evade immune defenses, allows the bacteria to adhere well to medical devices
What does selectively permeable mean?
allows the passage of some materials but not all materials move through freely
What is the glycocalyx?
an extracellular coating that provides protection to the cell
Plasmids typically carry _____ genes
antibiotic resistance ; nonessential
Prokaryotic cells that are related to eukaryotes but similar in structure to bacteria are called _______
archaea
The main function of fimbriae is _______ to cells and other surfaces
attachment
A(n) ________ filament is a periplasmic flagellum found in some spirochete bacteria.
axial
Twisting or flexing of spirochete bacteria is attributed to its:
axial filaments
Peptidoglycans are components of the cell walls in ________.
bacteria
Why is it difficult to group bacteria into species?
bacteria can alter their genetic makeup, bacteria do not use a typical mode of sexual reproduction, bacterial cells can accept genetic material from other sometimes unrelated cells
The _____ is the name given to a structure external to and bound tightly to the cell wall that is made of polysaccharides and proteins and contributes to the pathogenicity of the organism
capsule
Which of the following structures is external and can protect the bacterial cell from various host immune responses?
capsule
Which of the following acts as a selective barrier between the internal and external contents of the cell?
cell membrane
Penicillin is ineffective against Mycoplasma because the organism lacks a ________ ___________ which is the primary target of penicillin.
cell wall
The ______ ______ is the structure used by the Bergey's Manual of Determinative Bacteriology to classify bacteria into taxonomic divisions such as Gracilicutes and Firmicutes.
cell wall
What structure is used in the Bergey's Manual of Determinative Bacteriology to divide prokaryotes into four major divisions?
cell wall
The prefix "strepto" is used to indicate that the cells are arranged in ?
chains
To move towards a chemical attractant by flagellar motion is referred to as positive
chemotaxis
The hereditary material of a bacterial cell is a (normally) single circular strand of DNA known as the bacterial _______, which is aggregated in the nucleoid
chromosome
The genetic exchange of material through pili is termed _____
conjugation
The genetic exchange of material through pili is termed __________
conjugation
The correct order of the four reagents of gram stain?
crystal violet, gram's iodine, alcohol, safranin
The internal gelatinous matrix of a cell, mostly composed of water, is referred to as _________.
cytoplasm
The ______ is a network of actin and tubulin filaments tat are located just under the cell membrane and that contribute to cell shape
cytoskeleton
What internal structure contributes to cell shape and division?
cytoskeleton
In bacteria, sporulation is the process of ______ formation
endospore
Depletion of nutrients like carbon and nitrogen can result in the formation of ________ in some bacteria.
endospores
Diseases such as anthrax, tetanus, gas gangrene and botulism are caused by bacteria that are able to form?
endospores
______ are for cell survival under extreme environmental conditions, rather than reproduction.
endospores
The lipid portion of lipopolysaccharide (LPS) is also known as _____
endotoxin
What roles do teichoic and lipoteichoic acid play in gram-positive cells?
enlargement during cell division, maintenance of the cell wall, contribute to charge of the cell surface
What general word is used to describe a preference for an environment such as high heat or high levels of salt?
extremophile
Organisms such as the Archaea, are termed ________ because they are capable of living in very harsh environments
extremophiles
True or False: All prokaryotes have a cell wall
false
True or False: Penicillin is an effective antibiotic against Mycoplasma.
false
True or False: The cell wall of gram-negative bacteria is thicker than the cell wall of gram-positive bacteria
false
The lipid portion of lipopolysaccharide is known as endotoxin because it can cause:
fever and shock
Which appendage provides the ability to attach to surfaces and other cells?
fimbriae
_______ are used for attachment
fimbriae
The basal body, hook, and filament are components of _______ in prokaryotes.
flagella
The ______ is a polysaccharide protective coating outside of the bacterial cell wall that is called either a capsule or slime layer based on its structure
glycocalyx
The outer coating of many bacterial cells is called the?
glycocalyx
The ______ stain technique allows a microbiologist to differentiate bacteria based on their cell wall composition/structure
gram
What staining technique is most commonly used to differentiate most bacteria based on their cell wall structure?
gram stain
Lipopolysaccharide is a component of cell membrane of which cell type?
gram-negative cells
To determine whether bacterial cells are motile, one can observe them microscopically in a ________ drop slide.
hanging
Because endospores are resistant to ________, food must be canned using pressurized steam to ensure sterility
heat
Which group of bacteria grows at very high temperatures?
hyperthermophiles
Cytoplasmic _____ such as granules or vesicles, can store organic and inorganic nutrients and even gases or magnetic iron oxides
inclusions
Organic and inorganic nutrients can be stored in bacterial cells as:
inclusions
Organic and inorganic nutrients can be stored in bacterial cells as?
inclusions
What is the purpose of mycolic acid in the mycobactyerial cell wall?
it reinforces the cell wall and makes the bacterium resistant to certain chemicals and dyes
LPS is the abbreviation for _______
lipopolysaccharide
A tuft of flagella from a single site is referred to as a _______ arrangement, whereas flagella dispersed over the surface of the cell is referred to as _____
lophotrichous ; peritrichous
Cell breaking or rupturing is known as cell ______
lysis
_______ is what occurs when a cell breaks or ruptures
lysis
What roles do teichoic and lipteichoic acid play in gram positive cells?
maintenance of the cell wall; enlargement during cell division; contribute to charge of the cell surface
All bacteria possess a cell _______ but not all bacteria possess a cell _________
membrane ; wall
Organisms that are able to convert carbon dioxide and hydrogen into methane are known as __________
methanogens
Which type of organism converts CO2 and H2 into CH4 (methane)
methanogens
A cell wall and some form of glycocalyx are found in _______ bacterial cells.
most
The ability to move is referred to as __________
motility, self propulsion
The mycobacterial cell wall is reinforced with ______ acid
mycolic
The _____ bacteria have no cell wall but have a cytoplasmic membrane that is stabilized by sterols:
mycoplasma
The ______ bacteria naturally have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols.
mycoplasma
The _______ bacteria have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols.
mycoplasma
Bacteria that are in close proximity may communicate via structures known as _______
nanowires
Only gram-______ bacteria possess an outer membrane
negative
Only gram-_______ bacteria possess an outer membrane.
negative
To date, true pili have only been found on gram- ______ bacteria
negative
To date, true pili have only been found on gram- _______ bacteria
negative
Gram-______ cell walls are thinner than Gram-______ cell walls, providing them with relatively greater flexibility and sensitivity to lysis.
negative ; positive
Depletion of ___________ is the stimulus for the formation of endospores
nutrients
The phospholipid barrier surrounding the peptidoglycan layer in gram-negative bacteria is called the _______ membrane
outer
The phospholipid barrier surrounding the peptidoglycan layer in gram-negative bacteria is called the _______ membrane.
outer
The prefix "diplo" is used to indicate that cells are arranged in:
pairs
A major structural component of the lipid bilayer in a cell membrane are _________, which comprise 30-40% of the membrane mass
phospholipids
During ________, bacterial cells move by flagellar motion in response to light
phototaxis
Small proteinaceous appendages in gram-negative bacteria that function in DNA exchange are called conjugation ____
pili
A ______ is a hollow, protein tube that facilitates the transfer of genetic material between bacterial cells
pilus
An appendage which forms a channel for the exchange of genetic material during bacterial conjugation is called a ___________
pilus
A ______ is an extrachromosomal piece of DNA that contains genes not essential for cell growth.
plasmid
Which phrase means that a cell can have various shapes?
pleomorphic
Teichoic acid and lipoteichoic acid are:
polysaccharides embedded in the cell wall of gram-positive bacteria
________ are specialized proteins located in the outer membrane of gram-negative cells.
porins
Archaea are:
prokaryotic, more closely related to the Eukarya than the bacteria, often able to exist in extreme environments
What are porins?
protein channels that span the outer membrane
What two macromolecules make up the major components of cell membranes?
proteins ; lipids
A gram positive cell that has lost its cell wall and is now very susceptible to lysis is referred to as a:
protoplast
A gram-positive cell that has lost its cell wall becomes an L-form known as a.
protoplast
What is the primary function of the capsule?
provides protection
Refrigerators are excellent environments to encourage the growth of ________
psychrophiles
Which group of bacteria grows at very low temperatures
psychrophiles
Proteins are synthesized on the _______, a small spherical structure located int he cytoplasm or attached to the rough endoplasmic reticulum (RER)
ribosome
The site of protein synthesis in a cell, known as the ________ , is composed of rRNA and protein.
ribosome
Which organelle is responsible for synthesizing protein?
ribosome
Which organelle's small and large subunits are composed of rRNA and protein?
ribosome
Which structures are possessed by ALL bacteria?
ribosomes, cell membrane, chromosomes
Counterclockwise rotation of the flagellum causes a bacterial cell to swim or ______ towards a stimulus, interrupted by clockwise rotation in which the cell _____ and changes its course
run ; tumble
The cell membrane is a _____ permeable barrier of the cell
semi
One way to detect motility in the laboratory is to stab cells into what kind of medium?
semisolid
______ refers to a specific member of a species based on the host's antibody response.
serotype
______ refers to a specific member of a species based on the hosts antibody response
serotype
Choose the characteristic that is true for archaea but not bacteria
similar ribosome structure to eukaryotes
Some bacteria are covered with a loose shield called a ________ _______ that protects the cell from dehydration and loss of nutrients
slime layer
a type of glycocalyx called the _____ is loosely attached to the bacterial cell and protects it from dehydration and loss of nutrients.
slime layer
The two types of glycocalyx in bacteria are:
slime layer ; capsules
A "strain" is a subgroup of a _____.
species
A "strain" is a subgroup of a ________.
species
A "type" is a subgroup of a bacterial _______
species
A gram negative cell that has lost its cell wall but retained part of its outer membrane is referred to as a:
spheroplast
The L-form that arises when gram-negative bacteria lose their cell wall but retain part of their outer membrane is called a.
spheroplast
______ is the process of endospore formation
sporulation
The prefix "______" means "in a chain"
strepto -
What is the primary function of endospores?
survival
Which structure accounts for the different results of the Gram stain
the cell wall
True or False: A nucleus is surrounded by a membrane but a nucleoid is not
true
True or False: Bacterial endospores are more resistant to disinfectants than vegetative cells.
true
True or False: Endospores are resistant to ordinary boiling
true
True or False: Mycoplasmas are pleomorphic
true
Which is more impervious to the action of antimicrobial chemicals?
typical gram negative bacteria
A curved bacterial cell is a:
vibrio
The gram stain differentiates bacteria based upon structural differences of the bacterial cell ________
wall
The cell envelope is composed of cell _______ and the cell _______
wall ; membrane
The following are required for endospores to germinate.
water, a specific chemical or environmental stimulus
Domain Archaea is most closely related to Domain _________ because they share rRNA sequences and similar ribosomal structure/function
Eukarya
Which of the following diseases are caused by endospore forming bacteria?
Botulism, Anthrax, Tetanus
Which structures are possessed by the majority of but not all bacteria?
Cell wall, glycocalyx
Bergey's Manual of ______ Bacteriology is used by microbiologists whose primary interest is identification of prokaryotes, while Bergey's Manual of _________ Bacteriology is used by those who are also interested in the evolutionary relationships of prokaryotes.
Determinative ; Systematic
True or False: Endospores are resistant to ordinary boiling
True
