Microbiology Ch. 12-13
The group of fungi in which sexual reproduction has not been observed is
Deuteromycetes
Why would all protozoa be expected to require large amounts of water in their habitats?
NOT all of the above are correct
What part of E. coli T4 phage attaches to the host cell receptors
Protein fibers at the end of the phage tail
The site at which a virus has infected and subsequently lysed the infected cell, releasing its progeny to infect and lyse surrounding cells, thereby forming a "clear zone", is referred to as
a plaque
Diseases of short duration frequently followed by long-term immunity are referred to as
acute infections
Convergent evolution
explains the morphological similarity yet major genetic differences found between slime molds and fungi AND refers to two different organisms that develop similar characteristics in adaptation to similar environments
An exit method used by viruses which does not immediately destroy the host bacterium is
extrusion
What are two ways that phage can replicate in harmony (not directly lysing) their host cell
extrusion and lysogeny
In the region of budding, the inside of the plasma membrane becomes coated with
matrix proteins
A temperate phage
may be lysogenic AND enters a lysogenic or lytic life cycle shortly after entering the host cell
Cells taken from a tumor
may be used to grow viruses AND can be cultivated in vitro indefinitely
Lice and mites
may both be spread by personal contact
The term "segmented" refers to viruses that
may contain several pieces of RNA
Assembly of the T4 phage
may involve some self-assembly AND may involve the use of scaffolds
Outside of living cells, viruses are
metabolically inert
Fungi are classified according to their
method of sexual reproduction
Explain why HIV becomes resistant so quickly when a single drug is used therapeutically
not A check this one
Why do animal viruses have envelopes and phages rarely do?
not answer D check on this one
An infection in which the virus is continually present in the body is referred to as
persistent
Free-floating, photosynthetic organisms found in marine environments are
phytoplankton
A limiting factor for viral infection is
presence of specific receptor molecules on the host cell
Viruses
probably keep the numbers of bacteria in check AND are active in passing DNA from one bacterium to another
Phage-encoded enzymes are
produced in a sequential manner AND used to customize the cell for viral production
Gonyaulax
produces a non-protein neurotoxin AND is dinoflagellate
A virion is composed of
protein, either RNA or DNA, and possibly lipid
During attachment of phage to E. coli, the phage
randomly bump into the bacteria AND attach to proteins or carbohydrates on the bacterial surface
In the region of budding, the plasma membrane becomes involved with
spike proteins AND matrix proteins
RNA phages usually contain
ssRNA
Lyme disease is transmitted by
ticks
A varion is a(n)
complete, extracellular virus particle
Retroviruses are unique in that they
use RNA as a template to make DNA
Fungi capable of dimorphism grow either as
yeast-like or mycelium
Protozoan classification is based on their means of
locomotion
The phenomenon responsible for the ability of Corynebacterium diphtherium to produce the virulent toxin responsible for the devastating effects of diphtheria is called
lysogenic conversion
Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA are called
lysogenic phages
Fungal diseases are generally referred to as
mycoses
One group of animal viruses that are able to agglutinate red blood cells are the
myxovirus
Animal viruses are divided into a number of families whose names end in
-viridae
In the case of the T-even phages, the burst size is about
200 per host cell
The time from absorption to release for T-even phage is about
30 minutes
The pH at which most fungi thrive is
5.0
What is a defective phage
A virus that has lost some of its genetic material, and therefore cannot replicate within a new target cell
Prions
All of the above
Aflatoxins
All of the choices are correct
Fungi that are important for fermentation of fruits
All of the choices are correct
Regarding phage replication
All of the choices are correct
Spongiform encephalopathy occurs in
All of the choices are correct
The term filterable viruses was coined by
Beijerinck
The nucleocapsid is composed of
DNA or RNA and protein
Why would it be more difficult to treat diseases in humans caused by members of the Eucarya than diseases caused by the Bacteria?
Eukaryotic microbes use many of the same enzymes and systems as humans-so we lose the ability to target certain molecules that might be present ONLY in the cell type we want to eliminate. There's too much overlap when both organisms are eukaryotic.
Paralytic shellfish poisoning occurs when humans eat shellfish that have fed on
Gonyaulax spp
Why is it not surprising that AIDs patients frequently suffer a viral-induced tumor?
HIV genomes integrate into the host cell chromosome. This integration might result in loss of control of the cell cycle ( also known as cancer)
The concentration of virus that infects or kills 50% of the host cells is referred to as the
LD50 AND ID50
Which is filamentous phage
M13
How would increased travel lead to increased spread of multicellular eukaryotic parasites
Many eukaryotic parasites depend on vectors (often small blood-sucking insects) for transmission- so moving an infected individual into an area with new vectors and new susceptible humans would increase the spread of the illness
An antibiotic is added to a culture of E. coli, resulting in death of the cells. Bacteriophage are then added. Would the phage replicate in the E. coli cells? Why or why not?
No, b/c the virus would depend too much on having the active machinery of a living cell for its replication. Without the ability of the cell to try to replace what is lost/damaged/used as the virus goes through its life cycle, the virus couldn't reproduce effectively
Are all fungi detrimental (bad) for other organisms
No-fungi are sometimes good, sometimes bad for other organisms,. It really depends on which fungus you're talking about and the relationship it has with the other organism. Some fungi ,for example, can form a symbiotic relationship with plant roots that increases their nutrient and water absorption. This is good.
Is antigenic shift alone likely to lead to influenza pandemics
Not D check this one
Which dinoflagellate kills fish by dispersing toxins directly into the water
Pfiesteria
One of the greatest causes of human deaths through time has been due to
Plasmodium spp
Single-celled eukaryotic organisms that lack chlorophyll are called
Protozoa
You add an unknown phage to a mixture of F+ and F- cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F-. How can you explain this phenomenon?
The phage bound to a receptor on the sex pilus, and therefore only infected the F+ cells (leaving the F- cells alone).
Which of the following is not a characteristic of normal cells
They grow as multiple layers
Macroscopic algae possess a special structure that acts as an anchor and is commonly called
a holdfast
Prions are
an infectious protein
Sarcoptes scabiei
are responsible for scabies
Nematodes
are roundworms AND are found in the gastrointestinal tract or the blood
Mycorrhizae
are vital for the survival of many plants AND increase the absorptive ability of roots
Viruses may not be cultivated in
blood agar
The shape of the virus is determined by its
capsid
Bacteria infected with filamentous phages are termed
carrier cells
Once integrated, phage DNA can remain in the prophage state as long as
certain phage genes are repressed
All fungi have ____ in their cell walls
chitin
The changes that occur in virally-infected cells are referred to as the
cytopathic effect
Bacteriophages and animal viruses
differ b/c bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid
Viruses are commonly referred to by their ____ name
disease AND species
The common species name of the virus is based on the
disease the virus causes
If reasonably pure preparations of virus are available, the number of virus present may be determined by
electron microscopy
Diatoms are algae whose silicon dioxide-containing shells are useful economically as
filters
Which are not arthropods
flukes
Cells infected with animal viruses lyse b/c
functions necessary for cell survival are not carried out and the cell dies
In the late 19th century, immigration from Ireland to the U.S. occurred in high numbers due to an infection of potatoes by
fungi
Plant pathology grew in importance as a field of study after it was shown that the Irish potato blight was caused by
fungi
The return of carbon dioxide to the atmosphere and nitrogen to the soil is due to the action of
fungi and bacteria
The receptors to which animal virus attachment proteins usually bind are
glycoproteins
The best -known examples of viruses that cause latent infections are
herpes AND chickenpox
The integration of phage DNA into the bacterial chromosome occurs because of
identical DNA sequences in both
Fleas
if ingested, may transmit a tapeworm to children AND may transmit Yersinia pestis
The protein coat of a virus
is called a capsid, protects the nucleic acid AND is involved in recognition of host cell receptors
Resistance of some animals to certain viral diseases is based on
lack of specific receptors on the host cell
The terms yeast, mold, and mushrooms refers to fungal
morphology
A tangle of fungal hyphae is generally known as a
mycelium
Using phages to treat a bacterial infection is an interesting idea because
of the increasing problem of antibiotic resistance
Algae
often grow in areas where other forms of life may have difficulty
Filamentous phage
only infect E. coli that have pili
In latent infections, the virions are
only produced during reactivation
For which of the following processes are enzymes not required
self-assembly
There are ___ families of DNA containing viruses that infect vertebrates
seven
What part of the attached bacteriophage enters through the host cell wall
the nucleic acid