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Which of the following statements is false?
A. The grouping of microorganisms in a phylogenetic scheme that is based on nucleic acid sequence data is not always the same as the grouping of microorganisms in a taxonomic scheme based on morphological traits.
B. The cells of prokaryotic organisms are divided into compartments by internal membranes.
C. In the most popular current phylogenetic scheme, prokaryotic
organisms are divided into two domains called Bacteria and Archaea
D. Most if not all of the chemoautotrophic organisms on Earth are
prokaryotes.
E. The cells of prokaryotic microorganisms contain 70S ribosomes and most have circular chromosomes
B. The cells of prokaryotic organisms are divided into compartments by internal membranes.
The bacterial arrangement illustrated here is known as
(Attached at sides not head/tail)
A. Staphylococcus.
B. Palisades.
C. Pleomorphic.
D.Tetrad.
E. Streptobacillus.
B. Palisades.
When Pseudomonas aeruginosa is grown in LB under aerobic
conditions and then stained for biofilm formation the results are a
ring as shown for the left tube. When the bacteria are grown
anaerobically in the presence of arginine (Arg), the results on the
right are obtained. Which statement best explains the observed
results?
The P. aeruginosa bacteria used Arg to grow anaerobically, so that it no longer had to grow at the air-liquid interface, which allowed it to form a biofilm all over the tube wall
Listeria virulence is directly related to its ability to
live within cells and thus avoid exposure to the immune system
of its host.
Why do doctors caution patients who are pregnant to avoid deli meats, cold cuts, and soft cheeses?
The Listeria bacteria can easily grow in the uncooked food
stored in the refrigerator
Why do male teenagers typically have more acne than male adults?
The P. acnes bacteria overgrow during puberty when sebum is
abundant due to higher testosterone levels, particularly in males.
Which of the following is an advantage for a bacterium having the
ability to invade and reside inside host cells:
A. The bacteria can bind to antibodies and get transported to
lymph nodes.
B. The host cytosol is rich in nutrients, if access can be gained by
the bacteria.
C. The bacteria can colonize and form biofilms.
D. Multiple bacteria can use the host cell as a vesicle to exchange
metabolites with each other.
E. The host cell can shield the bacteria from viruses and parasites.
A toxin common to most Gram-negative bacteria is
lipid A.
A strain of the Gram-negative bacterium Neisseria gonorrheae, which
causes the sexually transmitted disease gonorrhea, has a mutation that has caused the bacterium to lose the ability to produce fimbriae and so it has become less avirulent as a consequence. What function has this pathogen lost?
The ability to adhere to a host cell.
Among the virulence factors produced by the Gram-positive
bacterium Staphylococcus aureus, the factor that contributes
to the ability of S. aureus to invade tissues is
hyaluronidase
Toxins are the sole cause of symptoms of
botulism from Clostridia.
Botulinum toxin is a _____________________ that binds to the synapses
of motor neurons and prevents release of the _____________________
resulting in temporary _____________________ paralysis of associated
muscle.
AB-type neurotoxin, acetylcholine neurotransmitter, flaccid
Although the proteins they transfer may be different, the type 3 secretion systems of Escherichia coli, Salmonella, Shigella, and Yersinia function similarly in that they _______.
transfer bacterial proteins from the bacterium into the host cell.
How do archaeal ribosomes differ the most from bacterial ribosomes?
C. The DNA in archaeal ribosomes differ from those in bacteria.
D. The proteins in archaeal ribosomes differ from those in bacteria.
E. The RNA in archaeal ribosomes differ from those in bacteria.
Which of the following is not a reason archaea thrive in extreme
environments?
A. Cytoplasmic enzyme composition
B. Cell membrane composition
C. Amino acid composition
D. Nuclear composition
E. DNA composition
Which of the following statements about archaea is true?
Archaea lack peptidoglycan in their cell walls
Simple eukaryotes that carry out photosynthesis are known as
algae.
Which of the following are not eukaryotic microbes?
Archaea
A unicellular fungus is a _________, while masses of long,
intertwined fungal __________ are called ___________.
yeast / hyphae / mycelia
Fungal hyphae that lack cross walls are called ___________.
aseptate hyphae
Which of the following do not have hyphae associated with them?
B. mushrooms
D. lichens
????
All truly pathogenic fungi exist in the environment as molds but
grow in the body as spherical yeasts. This trait is known as ______.
A. morphogenesis
B. mushrooming
C. morphotype shift
D. dimorphism
E. anamorphism
Which of the following statements ab out Candida is FALSE?
Candida can be easily treated with topical antifungals in
immunocompromised individuals.
Ringworm is caused by _________.
dermatophytes growing in the outer dead tissue layers
of the skin
The most common source of tinea cruris (jock itch) is _________.
spread from feet
Most mycoses are difficult to treat because _________.
treatment causes major disruption of the microbiota ??
The deadliest mushroom toxin is produced by ____________.
Amanita phalloides
Which of the following is not true of aflatoxins
They are produced by Penicillium.
______ are the environmental reservoir for infection with
Cryptococcus neoformans.
Birds
Opportunistic fungi that can be pathogens in some people ______.
are part of the normal microbiota for many individuals
Healthy humans typically become infected with Toxoplasma gondii
by ______.
Ingesting undercooked meat containing T. gondii
The fever that is associated with malaria is primarily a result of ______.
A. lysis of hepatocytes
B. reproduction of Plasmodium inside erythrocytes
C. lysis of leukocytes
D. lysis of Plasmodium trophozoites
E. release of a toxin from Plasmodium
What are the minimal components of a virus?
DNA or RNA and protein ???
Which type of nucleic acid is not found in the genome of viruses?
Circular, single stranded RNA
Which statement MOST accurately describes lytic viral replication?
Viral replication usually results in the death and lysis of the host cell.
The period of time required to complete the lytic cycle is called
the burst time
Bacteriophages are part of our microbiome?
True
Which of the following processes is not part of the lysogenic cycle of
bacteriophages?
Host-cell lysis
During the synthesis phase of a double-stranded DNA animal virus depicted below, correctly name the host-cell processes that are hijacked by the virus.
1 = Transcription 2 = Translation 3 = Replication
What is not a reason an animal virus would want to have a host cell
envelope around its capsid?
A. To avoid the host cell cytoplasm
B. To provide extra protection from the environment
C. To avoid killing its host
D. To hide from the immune system
What enzyme allows HIV to go against the "Central Dogma" of molecular
biology?
Reverse Transcriptase
What led to polio being eradicated in the Americas?
A widely available cost-effective vaccine
