ALL eaukaryotes contain
mitochondria
hydrogenosomes
a membrane-enclosed nucleus
all of the above
The endoplasmic reticulum is
continuous with the Golgi apparatus
located around the nuclear membrane but is not in actual contact with it.
a network of membranes continuous with the nuclear membrane.
all of the above.
The Golgi apparatus functions to
modify and secrete proteins to the external environment
sort proteins used within the cell
synthesize protiens
both modify and sort proteins into those destined for secretion and those that function in membrane structures
The foraminifera
are a major component of the White Cliffs of Dover
have shells known as tests
inhabit coastal marine environments
are all of the above
Which statement BEST describes the habitats of the fungi?
Most terrestrial fungi are animal parasites
Most fungi are aquatic, primarily marine aquatic
Most fungi are terrestrial and inhabit soil or dead plant matter
Most fungi are aquatic, primarily freshwater aquatic
Diatoms are
more closely related to slime molds than to algae
a type of fungus
morphologically symmetric
Which algae are MOST closely related to plants?
euglenoids
red algae
brown algae
green algae
Where within a eukaryotic cell is ribosomal RNA (rRNA) synthesized?
lysosome
cytoplasm
mitochondrion
nucleolus
What phenomenon accounts for the appearance of chloroplasts in some unicellular phototrophic eukaryotes?
endosymbiosis
sequencing of chloroplasts' SSU genes
secondary endosymbiosis
none of the above
The membrane-enclosed compartments that contain digestive enzymes in eukaryotic cells are called
mitosomes
lysosomes
stromas
cristae
Which microbial group is responsible for massive amphibian die-offs worldwide?
chytrids
zygomycetes
ciliates
cercozoans
Which of the following is NOT a member of the Eukarya?
protists
fungi
viruses
The amoebozoa use what structure for movement and feeding?
cilia
threadlike pseudopodia
lobe-shaped pseudopodia
flagella
Agents that kill bacteria are said to be
bacteriostatic
bacteriocidal
inhibitory
The complete elimination of all microorganisms include viruses is called
disinfection
decontamination
sterilization
any of the above
The process by which macromolecules lose their structure and ability to function is called
thermal death
denaturation
UV radiation is antimicrobial, because
radiation generates magnetic poles that denature the cellular components
radiation generates significant amounts of heat within the given cell
energy present causes modifications or breaks in the DNA molecules
all of the above are true
Ergosterol inhibitors specifically target
bacteria
eukaryotes
A ________ filter is most often used to filter sterilize liquids.
microbistat
nucleation track
depth
membrane
The action of some bacteriolytic chemical agents can be observed by noting a(n)
decrease in turbidity of the medium
change in the color of the medium
increase in the turbidity of the medium
change in the surface tension of the medium
In the agar diffusion method of studying antimicrobial action, the _______ is measured.
turbidity of the medium
diameter of the zone of inhibition
distance between the microbial colonies
diameter of the individual microbial colonies
Polyoxins interfere with
chitin biosynthesis
fungal mitosis
cell membrane synthesis
Of all known antibiotics that have been identified in nature, _________ are clinically useful.
8-10%
<1%
25-30%
18-20%
Semisynthetic antibiotics
are natural antibiotics that have been purified by artificial means
have an artificially constructed core that stimulates the production of "natural products"
are natural antibiotics that have been chemically modified in the laboratory
are found in nature, but their rate of production is enhanced in the laboratory
Important targets of antibiotics in Bacteria are
DNA replication and transcription elements
the cytoplasmic membrane
the cell wall
At present, the penicillins and the cephalosporins account for ___________ of all the antibiotics produced and used worldwide.
less than 10%
well over 70%
over 50%
about 25%
The B-lactam antibiotics
inhibit cell wall synthesis
inhibit protein synthesis
inhibit plasma membrane synthesis
prevent chromosomal replication
The absorption of _________ by chlorophylls begins the process of _________.
ATP / autotrophy
light energy / photosynthetic energy conservation
light quanta / autotrophy
ATP / photosynthetic energy conversion
In photosynthesis NADH and NADPH are produced from NAD+ and NADP+ by
oxidation reactions
reduction reactions
both oxidation and reduction reactions
neither oxidation nor reduction reactions
During oxygenic photosynthesis,
oxygen is produced
oxygen functions as a catalyst
oxygen is consumed
Which statement is TRUE?
The cytochromes contain iron atoms; chlorophyll contains a magnesium atom at the center of the porphyrin ring
The cytochromes contain magnesium atoms; chlorophyll contains an iron atom at the center of the porphyrin ring
Both the cytochromes and chlorophyll contain an iron atom but not magnesium atom
Both the cytochromes and chlorophyll contain magnesium atom but not iron atom
Carotenoids
are involved in the capture of light energy
function primarily as photoprotective agents
are hydrophobic pigments that are present in photosynthetic membranes
do all of the above
The process by which electrons from the quinone pool are forced against the thermodynamic gradient to reduce NAD+ to NADH is called reverse
electron flow (reverse electron transport)
reduction
proton motive force
energy flow
The Calvin cycle
requires both ribulose biphosphate carboxylase and phosphoribulokinase
is responsible for the fixation of CO2 into cell material
utilizes both NAD(P)H and ATP
does all of the above
The rapid and simplistic method of assaying for nitrogenase activity uses
one of several techniques, all of which require oxygen to be absent in the assay
growth tests that add different nitrogen sources into media
the acetylene reduction assay that exploits the nonspecificity of nitrogenase
mass spectrometry to observe 15N assimilation
In most caes, the final product of sulfur oxidation is
elemental sulfur
sulfate
hydrogen sulfide
thiosulfate
Ferrous iron oxidation generally occurs in environments with
alkaline condition
little or no light present
high oxygen content
high H+ concentrations
The reduction of N2(g) for use as a source of nitrogen for biosynthetic needs is called nitrogen
assimilation
oxidation
fixation
The only organisms that perform photosynthesis are ones that produce some form of
carotenoids
phycocyanin
chlorophyll or bacteriochlorophyll
phycoerythrin
What compound do most chemolithotrophs use as a source of carbon?
carbon dioxide
organic sources other than glucose
inorganic compounds
glucuse
Most protists are motile.
The biochemical reactions in the hydrogenosome are focuses on pyruvate oxidation.
Because H2 levels in oxic environments are transient, it is likely that aerobic hydrogen bacteria shift between chemoorganotrophy and chemolithotrophy depending on levels of organic compounds and hydrogen in their habitats.
The earliest diverging lineage of fungi are the
chytridiomycetes
ascomycetes
glomeromycetes
Peroxisomes
originate in the cell by incorporating proteins and lipids from cytoplasm
divide in synchrony with the cell
become membrane enclosed
Which statement is TRUE? Fungal cell walls
resemble plant cell walls chemically but not structurally
resemble plant cell walls structurally but not chemically
resemble plant cell walls both chemically and structurally
do not resemble plant cell walls either chemically or structurally
Neuraminidase inhibitors such as oseltamivir and zanamivir are used to treat which type of infection?
fungal
bacterial
influenza virus
parasitic
Antimicrobial drugs are often grouped according to
molecular structure
mechanism of action
spectrum of antimicrobial activity
The vegetative cells of Mycobacterium tuberculosis are resistant to many germicides because of
the waxy nature of the cell wall
an extra membranous layer between the cell wall and the plasma membrane
the complex nature of the plasma membrane itself
the lattice work found in the glycocalyx
The thermal death time is the
dose of radiation necessary for a tenfold reduction in the numbers of selected microorganisms or biological factors
time it takes to kill all cells at a given temperature
time required for a tenfold reduction in the population density at a given temperature
measure of the radiation energy output from a source
Cold sterilization is performed using
compounds such as ethylene oxide
high-pressure chambers
exceptionally low temperatures
dry ice
The time required for a tenfold reduction of the variability of a microbial population at a given temperature is called the ______ time.
temperature-dependent logarithmic death
decimal reduction
mean sterilization
Whether an organism is classified as a photoheterotroph or a photoautotroph depends on its
oxygen requirements
carbon source
energy source
Photosynthesis is most correctly defined as the
absorption of light energy to produce carbohydrates
conversion of light energy to chemical energy
conversion of carbohydrates into energy-yielding organic products
production of carbohydrates by a plant or plantlike organism
Oxygenic phototrophs use light to generate
NADPH
ATP
organic carbon
both ATP and NADPH
Due to the sensitivity of dinitrogenase reductase, nitrogen fixation is inhibited by
oxygen
hydrogen
ammonia
Difinitive proof of N2 fixation is obtained using
an isotope of nitrogen, 15N, as a tracer
spectrophotometry to measure the opacity of possible nitrogen-containing substances
electrophoresis to analyze the shifts in nitrogen content
gas chromatography to assay for nitrogen uptake
Plastocyanin is a
membrane-bound sac found in certain bacteria
blue-green bacterium known for its unusual photoreactive complex
copper-containing protein in photosystem II that donates electrons to photosystem I
photosynthetic pigment found in some bacteria
The path of electron flow in oxygenic phototrophs is referred to as the ______ scheme.
Q
S
Z
E
Decalcification of the tooth enamel due to production of high concentrations of organic acids in the mouth is known as
degenerative plaque
dental caries
microbial enamel decalcification
dental plaque
Pathogenicity is
the ability of the hose to inflict damage on the pathogen
the ability of the pathogen to inflict damage on the host
the ability of the host to resist damage by the pathogen
Mucous membranes are frequently coated with a protective liquid called
mucus
epithelial fluid
membrane fluid
Two organisms that both benefit from each other are in symbiotic relationship called
parasitism
ammensalism
mutualism
commensalism
A microbiome contains all
viable cells in a particular location
organisms present in and on the body
living organisms present on the skin
organisms within the digestive system
Compared with decontamination, disinfection is
less aggressive
equally aggressive
more aggressive
either more or less aggressive depending on the situation in question
