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62 Cards in this Set

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Biological classification(8)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Scientific nomenclature
Binomial nomenclature
Each organism designated by two names
Genus
Specific epithet
Species names
Latinized
Underlined or italics
Genus name is capitalized; not specific epithet
Example:
Escherichia coli
Homo sapiens
Methods of classification
Numerical taxonomy
equal weight to all characters
measure many characters
many strains
calculate percentage shared characters
similarity coefficient (SJ)
dendograms
illustrate relationships
Traditional Methods
Morphology
shape
cocci, bacilli, spirilla
arrangement
singly, chains, clusters
flagella arrangement
Gram reaction
gram-positive, gram-negative
Traditional Methods
Biochemical and Physiological
growth requirements
end products
enzymes produced
carbon source
oxidation/reduction measurement
tetrazolium dye
fermentation properties
acids, gases
Traditional Methods
Viruses that infect bacteria are called
Serology
antibodies
highly specific for target molecules
distinguish between closely related
strain differentiation
Phage typing
viruses that infect bacteria
pattern of strains attacked by specific phage
host range of phage is narrow
Genomic methods: Percent G+C
Fraction of guanine-cytosine pairs
melting point of DNA
density measurements
% G+C indicate relatedness
values vary
similarities do not prove relatedness
Genomic methods:
Hybridization
DNA hybridization
heat DNA to separate strands
single strands from different sources are mixed
anneal in certain regions
amount of annealing determined by genetic relatedness
Genomic methods: Probes
Probe is tagged
fluorescent dye
chemiluminescent molecule
radioactive elements
specific for certain organism
cell DNA is lysed
anneal in certain regions
amount of annealing determined by genetic relatedness
Ribosomal RNA as probe
Isolate rRNA from cell
Add DNA primer
Reverse transcriptase
makes cDNA
Destroys RNA
Duplicate ssDNA
RNA Polymerase
Multiple rRNA copies of dsDNA
Genomic methods: Sequence
DNA Sequencing
ultimate tool of taxonomy
genome sequencing most accurate
formidable task--large size of genomes
4.5 million base pairs in E. coli
Ribosomal RNA genes
small ribosomal subunit
all cellular organisms contain
rRNA evolves more slowly
highly conserved
Protein encoding genes
Dichotomous keys
Series of questions
General questions
Divide into larger groups
Specific questions
Result in smaller groups
The genealogical tree of prokaryotes is divided into two domains _________________
& __________________.


Domain ____________________ (contains twenty-three phyla)
Prokaryotic genealogical tree
Based on 16S ribosomal RNA
Two domains
Archaea
Two phyla
Bacteria
23 phyla
Domain ___________________ (contains two major phyla)

1.._____________________ -

2.._____________________ -
A1 Crenarchaeota
One class
Morphologically diverse
Metabolically diverse
A2 Euryarchaeota
Five classes
Methanogens
Extreme halophiles
Thermoacidophiles
Domain Bacteria
I. _____________________________________

A.

B.


II. __________________________________________
B4 Deinococcus-Thermus
Deinococcus radiodurans
Resistance to radiation
Thermus aquaticus
Production of Taq polymerase
B5 Chrysiogenetes
Single species
Anaerobic respiration using arsenate
Domain Bacteria

III._______________________________________________

A.

B.
B10 Cyanobacteria
Oxygenic photosynthetic bacteria
Once called blue-green algae (not algae)
Major nitrogen fixer
Carbon from CO2
Nitrogen as N2
Heterocysts
Specialized cells for fixation of nitrogen
Photosynthesis in other cells
Domain Bacteria


IV.________________________________________________

A.

B.

V. _________________________________________________
(largest phyla of bacteria; contains 5 major classes)
B11 Chlorobi
Anoxygenic phototrophic bacteria
Anaerobic environments
Photosynthetic
Found in deep, clear bodies of water
B12 Proteobacteria
Largest phylum
1300+ species
Alphaproteobacteria class
Betaproteobacteria class
Gammaproteobacteria class
Deltaproteobacteria class
Epsilonproteobacteria class
Alphaproteobacteria
A.___________________________________
1.

2.

3.

4.
Environmentally important genera
Acetobacter
Production of acetic acid in vinegar
Agrobacterium
Produce cancerlike disease of plants
Ti plasmids
Rhizobium and Bradyrhizobium
Symbiotic nitrogen-fixing bacteria
Root nodules of legumes
Appendaged bacteria
Prosthecate bacteria—found in aquatic environs
Betaproteobacteria
B.__________________________________________

1.
2.
3.
Bordetella
B. pertussis—causes whooping cough
Neisseria
N. meningitidis—meningitis
N. gonorrhoeaea—gonorrhea
Sheathed bacteria
Tube surrounding bacteria
Contaminated water and sewage treatment
Gammaproteobacteria

C.___________________________________________

1.

2.

3.

4.
13 orders
Enterobactgeriales
Contain the enteric bacteria
Include human pathogens
Salmonella typhi
Shigella spp.
Yersinia pestis
Escherichia coli
Vibrionales
Curved rods
Vibrio chlerae--cholera
Pasteurellales
Pasteurella and Haemophilus genera
Pseudomonales
P. aeruginosa
Deltaproteobacteria

D.___________________________________________

1.

2.
Sulfur-reducing bacteria
Sulfates and sulfur to hydrogen sulfide
Mud flats, brackish water
Desulfovibrio spp.
Black metal sulfides of Black Sea
Gliding Fruiting bacteria
Myxobacteria
Soil organisms
Epsilonproteobacteria

E.____________________________________________
Campylobacter
C. jejuni—diarrheal illness
Helicobacter
H. pylori—gastric ulcers
Domain Bacteria

VI. ___________________________________

A. Three classes:
1.
2.
3.
B13 Firmicutes
Three classes
Clostridia
Endospore forming
Strict anaerobes
Bacilli
Endospore forming
Aerobic and/or facultative anaerobes
Mollicutes
Lack cell wall
Mycoplasmas
Gram-positive cocci
Spread between Clostridia and Bacilli classes
Domain Bacteria

B. Gram + cocci:
1.
2.
3.
B13 Firmicutes (continued)
Gram-positive cocci
Arrangement important for identification
Physiological differences
Staphylococcus
Facultative anaerobes
Four genera produce lactic acid
Streptococcus spp.
Leuconostoc
Pediococcus
Lactobacillus
Domain Bacteria
VII. ______________________________________
A.

B.

C.
Actinobacteria
Oddly shaped bacteria
Arthrobacter genus
Change shape during growth
Bifidobacterium genus
Irregular branched cells
Propionibacterium acne
Corynebacterium diptheriae
Acid-fast
Mycobacterium
Tuberculosis and Hansen’s disease
Nocardia
Spore-forming
Actinomycetes
Abundant in soil
Domain Bacteria
VIII._________________________________________________

A.
B.
C.
B16 Chlamydiae
Obligate intracellular parasites
Complicated reproductive cycle
Reticulate body
vegetative cell
multiplication
Elementary body
Chlamydiospore
Spread of infection
Domain Bacteria

IX._________________________________________________

A.

B.

C.

D.

X._________________________________________

A.

B.

C.
B17 Spirochaetes
Helical shape
Corkscrew motility
Flagella—two axial filaments
Metabolically diverse
Causes of human disease
Treponema pallidum—syphilus
Leptospira interrogans—leptospirosis
Borrelia burgdorferi—Lyme’s disease
Domain Bacteria

XI. ______________________________________

A.

B.
B20 Bacteroidetes
Purple nonsulfur bacteria
Photosynthetic
Bacteroides
Mouth and intestinal tract
B21 Fusobacteria
Oral and respiratory systems
F. periodonticum
dental abscesses
F. nucleatum
Respiratory system
Fungi
General characteristics
heterotrophic
nonphototrophic
absorptive
saprophytic
decompose to obtain nutrients
some pathogens
Fungi
B. Morphology
1. Consists of interconnected branched filaments
a. individual filaments are called _____________ (composed of chitin)
b. mass of filaments is called a __________________
Morphology
interconnected branched filaments
Hyphae
individual filaments
Mycelium
connected hyphae
coenocytic--undivided
septa--incomplete divisions
Fungi
2. ______________= body of the fungus
a. _______________=single cell (descriptive, not taxonomic)
Most used industrially = ________________________
b. ________________- form open, wooly mycelium
c. _________________-refers to the ability to express both forms
d. ________________________-fruiting structure of a fungus
(ex. Mushroom)
Thallus
body of the fungus
Yeasts
single cells, oval shaped
Molds
mycelium
Dimorphic
stages of both yeast and mold
Fleshy fungi
fruiting structures
mushrooms
Fungi
C. Reproduction
1. Asexual (no fusion of gametes)
a.
b.
c.

2. Sexual – spores involve the fusion of gametes
Reproduction
Classification based on reproduction
Assexual
elongation and fragmentation
budding
division of cells
asexual spores
sporangiospores
conidiospores
Sexual
spores
sexual fusion of gametes
Fungi
D. Lower Fungi ( all are ______________)
Major classes include:
1._______________________________-water molds; flagellated gametes
2._______________________________-water molds; non-motile sexual spores
3. _______________________________ - terrestrial mold; diseases=zygomycoses
Lower Fungi
Coenocytic
Five classes
Chytridiomycetes
Water molds
Gametes motility by flagella
Oomycetes
Water molds
Nonmotile sexual spores
Zygomycetes
Terrestrial molds
Disease: zygomycoses
Fungi

E. Higer Fungi (_____________ hyphae)
Major classes include:
1. _________________________ - ascospores
2. _________________________ - basidiospores
3. _________________________ - no sexual spores
Higher Fungi
septate hyphae
Ascomycetes
ascospores
Basidiomycetes
basidiospores
mushrooms
Deuteromycetes
no sexual spores
Penicillium
Fungi and Plants
F. Plant Diseases ( fungi are major cause)
1. ________________________ - two devastating genera
a. _____________________ - attacks young plants
b. ______________________-Ex. Irish potato blight

2. Some element of control by ___________________________________
Plant diseases
Lower fungi
Pythium spp.--Damping off
Phytophthora infestans--Potato tuber slime
Phytophthora ramorum--Sudden oak death
Higher fungi
Many diseases
Apple scab, corn smut, Dutch elm disease
Control
Anti-fungal sprays
Fungus-resistant plants
Fungi and Humans
G. Human Associated Disease
1. referred to as _________________________
2. not highly contagious, however difficulty in ___________________

H. Toxins
1. Muscarin-
2. A. phalloids-
3. Aspergillis-

*note: some are beneficial such as ________________________ and ___________________________
Human disease
Mycoses
Most often acquired from nature
Treatment is difficult
Toxins
Muscarin
Amanita muscaria mushroom
Phalloidin and amanitin
A. phalloides mushroom
Ergot
Claviceps purpurea—mold on rye
Aflatoxin
Aspergillus spp.
Black mold toxin (sick building syndrome)
Stachybotrys chartarum
Algae
II. Algae
A. General Characteristics
1. photosynthetic – similar to chlorophyll found in _____________, able to generate ___________, and able to utilize __________
2. range from microscopic singe cells to huge multi-cellular organisms
3. lack tissue differentiation
4. reproduce by unicellular asexual spores and gametes
5. mostly motile by ___________________

B. Ecology
1. mainly found in _______________ environments
2. __________________ - can live inside other organisms
3. commercially responsible for the production of _____________________ (thickener), ________________, and ______________________
Aquatic
freshwater
marine
Terrestrial
moist soil
tree bark
surface of rocks
Endophytic
live in other organisms
Varied environments
Commercial
Carageenan
thickener
Agar
Alginic acid
thickener
Food
protein supplement
animal food
Algae
C. Six groups are recognized according to their form ,structure of walls, and pigments they produce.
1. ____________________________ - euglenoids
2. ____________________________ - dinoflagellates
3. _____________________________-diatoms
4. _____________________________-green algae
5. _____________________________- red algae
6. _____________________________-brown algae
Classification
Six groups
form of thalli
wall structure
pigments
Euglenoids
Dinoflagellates
Diatoms
Green algae
Brown algae
Red algae
Lichens
III. Lichens (not organisms!)
1. composed of a ___________________ (dominant organism) and a(n) _____________________.
2. ___________________________ relationship
Mutualistic association
fungus
phototroph
algae
cyanobacteria
Protozoa

IV. Protozoa
A. General Characteristics
1.
2.
3.

B. Four groups based n motility
1. flagellates: _________________________
2. amoeba:____________________________
3. non-motile, all parasitic: _____________________________________
4. ciliates: _______________________________
Four groups
based on motility
Flagellate
Mastigophora
Amoeboid
Sarcodina
pseudopods
Sporozoa
nonmotile
Ciliate
cilia
Slime molds

C. Slime Molds
Two groups:
1.

2.

RNA containing viruses assemble in the
Not fungi
Two groups
True slime molds
Slimy, veined mass
Multinucleated cytoplasm
Cellular slime molds
Cells resemble amoeboid protozoa
Dictyostelium discoideum
Morphological changes in life cycle
Relatedness of Eukaryotes
Figure 12.19
Helminths

V. Helminths
A. Flatworms (AKA: __________________________________)
1.
2.
3.

B. Roundworms (AKA:________________________________)
Flatworms
tapeworms
scolex
attachment
hooks/sucker
germinal center
new segments
proglottids
segments
flukes
Roundworms
nematodes
Life Cycle of Beef Tapeworm
Figure 12.21
Arthropod Vectors
B. Roundworms (AKA:________________________________)

VI. Arthopod Vectors
1. A vector is an organism that _________________________________________________________________.
2. Provide a reservoir of _______________________________
3. ____________________________- refers to an infective organism (ex. Mites)
Reservoir of infection
mechanical vector
external transmission
not essential link
biological vector
part of life cycle
internal transmission
Arthropod Vectors
Reservoir of infection
mechanical vector
external transmission
not essential link
biological vector
part of life cycle
internal transmission
What is a virus?

The entire acellular viral particle is called a
= obligate, intracellular parasites that contain either
DNA or RNA; depend on synthetic machinery of host cell for replication
of the infectious particle called the virion
General characteristics viruses

The largest vertebrate viruses are the
Size - submicroscopic; most are beyond limit of resolution of light
microscope (exception = poxviruses; can be seen under light
microscope with proper illumination); size varies from 25 m to 250 m (approximately 0.1 diameter of E. coli cell)
Structural components
The type of nucleic acid found in viruses is
Viruses enter the host cell via both viropexis AND membrane fusion


The protective protein which surrounds the viral nucleic is called a
a. Nucleic acid core = genome - may be either DNA or RNA
but never both; may be either single stranded (ss) or double
stranded (ds); used in classification (ssDNA, ssRNA,
dsDNA, or dsRNA); may be either linear or circular; found
in all mature virus particles (virions)
b. Protein coat = capsid - shell surrounding and protecting
nucleic acid core; composed of identical subunits called
capsomeres; subunits undergo self-assembly into geometric
shapes around nucleic acid core; number of capsomeres is
unique for each virus; contain receptors that combine with
complementary sites on host cell surface for attachment;
found in all mature viruses
c. Envelope - lipid and protein membrane surrounding virion;
origin = host cell membrane; lipid of envelope make
viruses susceptible to lipid solvents and are more heat labile
than non-enveloped viruses; found only in viruses that exit
cell through cell membrane or bud through nuclear mem-
brane during maturation; viruses without envelope are
called naked
d. Glycoprotein spikes - surface projections coded for by
viruses; manufactured in host cell and become incorporated
into host cell membrane prior to virion maturation; often
act as receptors for host cells; may agglutinate rbc's
particles (virions)
Shape

The largest vertebrate viruses are the
a. Protein shell may assume either icosahedral (20 equilateral
triangular faces = cubic symmetry) or helical (rod-shaped
particles composed of repeating protein subunits surround-
ing core in a helical fashion = helical symmetry) shape;
some viruses (e.g. poxviruses) have a complex shape
Classification of Viruses
A. Criteria for classification
1. Nature of disease (e.g. neurotropic viruses)
2. Organ system most frequently involved (e.g. hepatitis viruses)
3. Physiochemical characteristics
a. Type of nucleic acid (ssDNA, ssRNA, dsDNA, dsRNA)
b. Presence or absence of envelope - ether sensitive are
enveloped while ether resistant = naked
4. Size (small = picornaviruses to large = poxviruses)
B. Vertebrate viruses classified into 13 families of RNA-containing viruses
and 7 families of DNA viruses
III. Replication Cycle

DNA viruses undergo maturation in the hosts
A. Attachment & adsorption - cell surface phenomenon; adsorption involves
specific interaction between sites on viruses and receptors on cell mem-
brane of host cell via ionic or electrostatic interactions (e.g. HIV attaches
via gp120 of virus to CD4 receptor on T cells); tropism = susceptibility
of only certain cells to particular viral agent - may be related to presence
or absence of receptors on host cell













B. Penetration - usually occurs by fusion (enveloped viruses) or phagocytosis
(naked viruses)

















C. Uncoating - involves removal of protein coat and release of viral nucleic
acid; may involve host enzymes (proteolytic) and/or viral coded enzymes
brought in with virus or synthesized in new host
D. Biosynthesis
1. Involves synthesis of viral nucleic acid, viral coat proteins and
virus-specific enzymes - each is synthesized separately
2. Site of viral synthesis varies depending on type of NA; general-
izations include:
a. Most DNA viruses synthesize DNA in nucleus of host cell
& proteins (structural & enzymatic) in cytoplasm
b. Most RNA viruses synthesize all viral components in cyto-
plasm
3. No infectious virus particles are detected during this period =
eclipse period
E. Maturation (Assembly of virions) - involves combining of synthesized NA
and protein; occurs in nucleus with most DNA viruses & cytoplasm with
most RNA viruses; most capsids self-assemble around genome; defective
(incomplete) viruses occur when NA is not coated by protein (empty coats
or non-viral NA placed in coat)



















F. Release
1. Host cell disintegration (lysis) - occurs when cell fills with virus
particles; causes death of cell and release of naked viruses
2. Slow release through cell membrane as part of budding process -
results in release of enveloped viruses; cell may not die for a long
time & can continue to shed virus particles; some proteins synthe-
sized under viral control become incorporated into CM of host and
become incorporated into virion as virus buds through membrane
(glycoprotein spikes); important in cellular immunity (proteins are
antigenic and host recognizes these proteins as foreign mounting
immune response against cells with these proteins in their mem-
branes)
IV. Effects of Viruses on Host Cells & Host Cell Responses
A. Effects of viruses on host cells = cytopathic effects (CPE) - morphologic
alterations that occur in virus-infected cells; often visible in light micro-
scope
1. Inclusions = intracellular structures; may be cytoplasmic or nuclear;
represent aggregates of viral nucleic acid or protein, mature virions
or degenerative cell reaction products; serve as markers of certain
viral infections (e.g. Negri bodies = intracytoplasmic inclusions of
rabies infection; Owl's eyes = cytomegaloviruses)
2. Syncytia (multinucleated giant cells) - represent fusion of virus-
infected cells with contiguous uninfected cells; form giant cells with
many nuclei; caused by virus-induced changes in CM; allows cell
to cell spread of virus without coming in contact with humoral
immunity (e.g. respiratory syncytial viruses)
3. Cell necrosis or death - rate of destruction depends on degree of
shut-down of host cellular functions and rate of synthesis with
accumulation of toxic viral structural proteins; cytolytic effects are
visible microscopically and when destruction is extensive, effects
can be seen with naked eye forming areas referred to as plaques in
tissue cultures; in vivo, destruction of large numbers of cells results
in impairment of tissue or organ structure & function
B. Host response
1. Non-immunological = interferon production
2. Immunological
a. Humoral - inhibits adsorption of virus to host cell surface
(blocks receptors on virus)
b. Cell mediated - acts against viral-specific proteins incor-
porated into host cell membrane; involves destruction of
infected cell by sensitized T cells
V. Laboratory Techniques with Viruses
Cell cultures which can be subcultured indefinitely are called
A. Viral isolation - require present of living cells
1. Laboratory animals - suckling animals usually more susceptible
than adult animals (e.g. suckling mice or guinea pigs)
2. Embryonated eggs - chick or duck eggs used most often; viruses
grow in embryo or on membranes
3. Tissue culture
a. Primary cell lines - prepared directly from tissue excised
from humans or animals (e.g. primary monkey kidney =
PMK cells)
b. Continuous cell lines - cells that have been passaged indef-
initely; are usually derived from malignant or premalignant
cells (e.g. HeLa from human cervical carcinoma and HEp-2 from human laryngeal carcinoma
B. Serological methods
1. Patient's serum - show rising titer of antibodies to specific viruses
2. Tissue culture - used to identify viruses that have been grown in the
laboratory; have specific antisera for viruses; most often show
neutralization of effect by antisera as indication of identity of virus
VI. Chemotherapy

Most RNA viruses obtain their envelope from the
A. Amantadine - synthetic amine; prevents penetration & uncoating of virion;
antiviral activity limited to influenza A virus; effective when administered
shortly before (prevent spread in epidemics) or shortly after contact with
virus
B. Vidarabine(Ara-A) - synthetic purine nucleoside; inhibits viral DNA
polymerases and cellular DNA & RNA polymerases; used primarily in
treatment of herpes simplex encephalitis, neonatal herpes simplex
and severe varicella and zoster infections in immunocompromised
C. Acyclovir - acts by inhibiting DNA polymerase; used to treat herpes-
virus infections; decreases symptoms - does not cure
D. Azidothymidine (AZT) - inhibits RNA and DNA polymerases & some
viral enzymes; used primarily in treatments of AIDS
VII. DNA viruses of interest
A. Herpesviruses
1. Characteristics
a. Relatively large viruses; dsDNA, linear core and icosa-
hedral capsid; enveloped
b. Replicate & assembles in nucleus - bud through nuclear
& cytoplasmic membranes during maturation & release
c. Require direct transmission - fragile; susceptible to drying
& inactivation by heat, mild detergents & lipid solvents
d. Virions spread from cell to cell at points of contiguous cell
contact leading to local spread of lesions - infections at
distant sites rare
e. Typically cause latent infections (recur for years)
2. Clinical manifestations
a. Herpes simplex - type 1 & 2
i. Keratoconjunctivitis - inflammation & swelling of
tissues of anterior eye; potential vision loss
ii. Cold sores (usually type 1)
iii. Genital lesions (usually type 2)
iv. CNS - meningoencephalitis & encephalitis
v. Typically cause latent infections (recur for years)
b. Varicella-Zoster
i. Varicella = chickenpox; primary disease; usually
epidemic; usually mild & self-limiting
ii. Zoster = shingles reactivation of latent varicella
virus; usually seen in later life; mechanism of
activation unknown; often associated with stress
c. Cytomegalovirus
i. Congenital (in utero) or neonatal disease most
common manifestation; may lead to mental retarda-
tion
ii. Infections of immunocompromised also seen; often
disseminated; individuals most likely = transplants
& individuals with AIDS
d. Epstein-Barr = infectious mononucleosis (acute, self-
limiting) & Burkitts lymphoma
3. Latency
a. Process not completely understood; appears not all viral
genes are expressed at all times leading to lack of viral
DNA and mature virion synthesis
b. Not known whether viral DNA integrated into chromosome
or remains a separate plasmid-like element
c. Viruses perist for life in nerve cells (herpes simplex &
Varicella-Zoster), in neutrophils & monocytes (VZ) & in
lymphocytes & salivary glands (CMV)
d. Reactivation produces symptoms - may be triggered by
sunburn, systemic infections, immune impairment,
emotional stress & menstruation
4. Prevention & Control
a. Avoid sexual contact during active genital infections
b. Administration of specific human immune globulin
promptly after exposure - used to prevent chickenpox in
immunodeficient children
c. Administration of live attenuated vaccine (chickenpox)
d. Treatment = acyclovir; decreases duration & severity of
disease - no cure
B. Hepatitis viruses

The complete virion of the hepatitis B virus is called a

Hepatitis B infection can be prevented by

Viruses attach to a surface component on the host cell called a(n)
1. Viral agents
a. Hepatitis A (HAV) = ssRNA (picornaviruses or
enterovirus)
b. Hepatitis B (HBV) = dsDNA (hepadnavirus)
c. Hepatitis C (HCV) = ssDNA (thought to be related to flavi-
viruses)
d. Hepatitis D (HDV) = ssRNA ( viroid = naked viruses that
lack coat protein) surrounded by hepatitis B surface antigen
(delta agent) - defective HBV; infective only in presence of
HBV infection
e. Hepatitis E (HEV) = ssRNA (not presently classified)
2. Clinical manifestations - Epidemiology
a. HAV - can be asymptomatic or symptomatic with or with-
out jaundice; symptoms include GI (anorexia, vomiting &
pain in area of liver); does not become chronic nor result in
carrier state; relapses may occur; transmitted by fecal-oral
route (has been associated with food - most commonly
uncooked oysters harvested from feces-contaminated
waters); hygiene most important control measure; close
contacts may be given immune globulin; vaccine may be
available in a few years

b. HBV - 3 morphological forms found in infected individuals
= Dane particle (mature virion) + spherical & filamentous
forms (incomplete viruses; not infectious); clinically can be
asymptomatic to symptomatic with or without jaundice or
fulminant (hepatic encephalopathy occurs during acute
phase; eventually coma & death can occur; can become
chronic but most completely recover; been associated with
primary hepatocellular carcinoma; transmitted by parenteral
routes (tattooing, acupuncuture, ear piercing, shaving,
manicuring, drug abuse, transfused blood, etc) and by close
contact with contaminated secretions (saliva, urine, tears,
CSF & semen - not feces); control involves screening of
blood donors, sterilization of medical & dental instruments,
vaccine (Recombivax = yeast containing cloned viral
genes) for health care workers; treatment of chronic HBV
presently uses interferon- (induces remission in 25-50%
of cases); passive immunization following exposure uses
hepatitis B immune serum globulin (HBIG)

c. HCV - milder than HBV infection; persistent & chronic
infection common; cirrhosis may develop; may be asso-
ciated with primary hepatocellular carcinoma; most cases
are transfusion-associated but may follow non-parenteral
exposure

d. HDV (Delta antigen-associated hepatitis) - follows coin-
fection of liver with HBV or superinfection; associated
with progressive liver disease resulting in death, especially
in superinfections; transmission, control & treatment same
as HBV
e. HEV - symptoms similar to HAV; seen in waterborne
epidemics in developing countries
VIII. RNA Viruses of Interest

Retroviruses utilize the enzyme ________ to make a DNA copy of their RNA.
VIII. RNA Viruses of Interest
A. Retroviruses (possess a reverse transcriptase - allows virus to make a
dsDNA intermediate which can integrate into host genome)
1. Viral agents
a. Human Immunodeficiency Virus I & II (HIV)
b. Human T-cell lymphotropic retrovirus I & II (HTLV)
2. HIV
a. ssRNA, enveloped virus
b. Preferentially infects T helper cells (lymphocytes that
express the CD4 surface antigen = receptor for gp120
surface antigen of HIV)
c. Antigenic variability associated with variability in genome,
particularly segments associated with enveloped genes
d. Key indicator diseases = Kaposi sarcoma, P. carinii
pneumonia, cryptosporidiosis or isosporiasis with diarrhea
of more than 1 month, mucocutaneous herpes simplex
ulcers, CMV disease of more than 1 month, mycobacterial
infections (esp. MAC complex)
B. Picornaviruses
1. ssRNA - naked
2. Contain 2 groups of viruses
a. Enteroviruses (intestinal) = polioviruses, Coxsachie &
ECHO; may cause CNS infection (aseptic meningitis &
encephalitis)
b. Rhinoviruses (respiratory) = common cold; over 100
different strains recognized
3. Polioviruses (types A, B & C) prevented by vaccine
a. Salk = killed virus (injection)
b. Sabin = live attenuated virus (oral)
C. Orthomyxoviruses (Influenza viruses)
1. ssRNA - segmented genome and enveloped
2. Important antigens
a. Nucleoprotein - divides viruses into 3 types recognized =
A, B, and C
b. Hemagglutinin (H) - glycoprotein spike on surface of
virion; determines subtypes; attaches to neuraminic acid-
containing glycoproteins on surfaces of host cells; initiates
infection (receptor) and causes agglutination of rbc’s; anti-
body to this antigen prevents infection
c. Neuraminidase (N) - glycoprotein spikes on types A & B
but not C; determines subtypes; breaks bond between H
spike and cell surface; antibody not protective
d. Major changes in amino acid sequence of glycoprotein
spikes resulting in changes in subtypes occur at intervals =
antigenic shift; minor changes in amino acid sequence of
glycoprotein spikes resulting in decreased affinity of virus
for antibody to original spikes but no change in subtypes
occur during epidemics = antigenic drift
e. Influenza A undergoes both shift & drift; influenza B
undergoes drif but not shift; influenza C seems to be anti-
genically stable
f. Antigenic shift in virus often results in pandemics
3. Clinical manifestations (influenza A)
a. Acquired by inhalation; often asymptomatic; symptoms
include fever, chills, myalgia, sore throat & dry cough
b. Recovery occurs in several days; convalescents may take
weeks
c. Mortality low but number of cases usually high so numbers
of deaths can be significant
d. Death result of primary influenza pneumonia or secondary
bacterial pneumonia caused most often by Streptococcus
pneumoniae, Staphylococcus aureus or Haemophilus
influenzae
e. Elderly & persons with chronic diseases at high risk
4. Control & treatment
a. Vaccination of high-risk persons (formalin-inactivated
virus grown in eggs) best control; must be made new each
year to contain strain present in outbreaks for that year
b. Treatment = amantadine or rimantadine; reduce duration of
illness & virus shedding
D. Togaviruses (rubella)
1. ssRNA - enveloped
2. Produces mild disease in young children & adults - may be
inapparent or rash, low-grade fever & lymphadenopathy occur;
arthritis and arthralgia may occur in adults; complications rare
3. Infection in early pregnancy can be disastrous
a. The earlier in pregnancy the infection; the more severe the
damage; infection after 4th month usually not severe
b. Abnormalities include cataracts, glaucoma, deafness,
congenital heart disease & mental retardation
4. Transmitted by direct contact with infected respiratory secretions
5. Vaccine method of control = live attenuated vaccine; provides
long-lasting immunity; vaccine virus can infect fetus (vaccine
should not be given 3 months before conception or during preg-
nancy
Chapter 12
The kingdom Protista includes these two groups of microorganisms.

a. algae and bacteria

b. fungi and protozoa

c. algae and protozoa

d. algae and fungi


status: incorrect (0.0)
correct: c
your answer: d
feedback: Incorrect.

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2 Fungi

a. have a cell wall, require oxygen, absorb nutrients

b. are non-motile, multicellular, reproduce via spores

c. neither are non-motile, multicellular, reproduce via spores NOR have a cell wall, require oxygen, absorb nutrients

d. both are non-motile, multicellular, reproduce via spores AND have a cell wall, require oxygen, absorb nutrients


status: not answered ()
correct: d
your answer:


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3 Fungi have a cell wall made of

a. peptidoglycan

b. pectin

c. chitin

d. cellulose


status: not answered ()
correct: c
your answer:


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4 The major types of photopigments in plant-like protists include

a. all of these choices

b. carotinoids

c. chlorophyll a

d. chlorophyll b


status: not answered ()
correct: a
your answer:


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5 Plant-like protists accumulate starch reserves in regions of the chloroplast known as

a. macro-nuclei

b. pyrenoids

c. protoplasts

d. starch vacuoles


status: not answered ()
correct: b
your answer:


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6 Asexual reproduction in the plant-like protists may be accomplished by

a. all of these choices

b. spore production

c. fission

d. fragmentation


status: not answered ()
correct: a
your answer:


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7 Red tides are due to blooms of

a. all of these choices

b. diatoms

c. dinoflagellates

d. brown algae


status: not answered ()
correct: c
your answer:


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8 The plant-like protists all possess the photopigment

a. chlorophyll c

b. chlorophyll d

c. chlorophyll a

d. chlorophyll b


status: not answered ()
correct: c
your answer:


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9 The ________ algae are primarily marine algae.

a. brown and red

b. green and gold

c. red and golden

d. green and red


status: not answered ()
correct: a
your answer:


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10 Agar is a derivative of ________ algae.

a. brown

b. green

c. golden

d. red


status: not answered ()
correct: d
your answer:


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11 A unicellular plant-like protist which lacks a cell wall is called

a. diatom

b. euglena

c. dinoflagellate

d. kelp


status: not answered ()
correct: b
your answer:


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12 During the protozoan life cycle the actively feeding and reproducing form of the organism is called a

a. cyst

b. trophozoite

c. spore

d. none of these choices


status: not answered ()
correct: b
your answer:


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13 The structure of an animal-like protist required for sexual reproduction

a. none of these choices

b. micronucleus

c. macronucleus

d. pellicle


status: not answered ()
correct: b
your answer:


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14 A cavity in an animal-like protist, which directs food to a specific site

a. pellicle

b. none of these choices

c. cytostome

d. contractile vacule


status: not answered ()
correct: c
your answer:


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15 Group of animal-like protists, which are nonmotile or motile by means of gliding locomotion.

a. sporozoans

b. flagellates

c. amoebas

d. ciliates


status: not answered ()
correct: a
your answer:


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16 Group of animal-like protists motile by means of flagella.

a. sporozoans

b. flagellates

c. amoebas

d. ciliates


status: not answered ()
correct: b
your answer:


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17 Group of animal-like protists motile by cytoplasmic streaming and formation of pseudopods.

a. flagellates

b. amoebas

c. sporozoans

d. ciliates


status: not answered ()
correct: b
your answer:


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18 Group of animal-like protists motile by means of cilia.

a. amoebas

b. ciliates

c. sporozoans

d. flagellates


status: not answered ()
correct: b
your answer:


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19 Dart-like weapons on the surface of some ciliates.

a. trichocysts

b. trophozoites

c. none of these choices

d. cysts


status: not answered ()
correct: a
your answer:


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20 Life cycle form of Plasmodium released from liver cells during infection.

a. sporozoite

b. schizont

c. merozoite

d. trophozoite


status: not answered ()
correct: c
your answer:


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21 Filamentous mass of fungi.

a. hyphae

b. all of these choices

c. spores

d. mycelia


status: not answered ()
correct: d
your answer:


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22 Fungi that alternate between a mycelial form and a yeast form.

a. septate

b. yeast

c. dimorphic

d. none of these choices


status: not answered ()
correct: c
your answer:


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23 Microbes which undergo sexual reproduction.

a. fungi

b. amoeba

c. all of these choices

d. algae


status: not answered ()
correct: c
your answer:


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24 Sexual fungal spore contained within a sac.

a. zygospores

b. basidiospores

c. none of these choices

d. ascospores


status: not answered ()
correct: d
your answer:


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25 A lichen may have as one of its components.

a. algae

b. fungi

c. cyanobacterium

d. all of these choices
Chapter 13
Web Quiz

Assignment Name: Batzing, Microbiology: An Introduction, 1/E, Ch 13
Summary of Results
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1 The type of nucleic acid found in viruses is

a. DNA

b. neither DNA NOR RNA

c. both DNA AND RNA

d. RNA


status: incorrect (0.0)
correct: c
your answer: b
feedback: Incorrect.

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2 The protective protein which surrounds the viral nucleic is called a

a. nucleocapsid

b. capsid

c. capsomere

d. envelope


status: not answered ()
correct: b
your answer:


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3 Protein projections that cover the envelope surface and enable viruses to attach to host cells are called

a. capsomeres

b. spikes

c. virions

d. capsids


status: not answered ()
correct: b
your answer:


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4 The entire acellular viral particle is called a

a. capsomere

b. viroid

c. capsid

d. virion


status: not answered ()
correct: d
your answer:


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5 Viral nucleic acid and the protein capsid that surround the nucleic acid makes up the

a. capsid

b. capsomers

c. viroid

d. nucleocapsid


status: not answered ()
correct: d
your answer:


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6 Viruses that infect bacteria are called

a. phages

b. flaviviruses

c. bacterioviruses

d. arboviruses


status: not answered ()
correct: a
your answer:


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7 The largest vertebrate viruses are the

a. togaviruses

b. rhabdoviruses

c. filoviruses

d. poxviruses


status: not answered ()
correct: d
your answer:


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8 The complete virion of the hepatitis B virus is called a

a. Dane particle

b. capsid

c. deltavirus

d. poxviruse,


status: not answered ()
correct: a
your answer:


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9 Hepatitis B infection can be prevented by

a. use of a latex condom

b. sexual abstinence

c. vaccines

d. all of these choices


status: not answered ()
correct: d
your answer:


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10 A viral disease, which has been eradicated.

a. influenza

b. measles

c. Smallpox

d. polio


status: not answered ()
correct: c
your answer:


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11 Group of viruses usually transmitted by mosquitoes

a. retroviruses

b. rhabdoviruses

c. flaviviruses

d. herpesviruses


status: not answered ()
correct: c
your answer:


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12 Most RNA viruses obtain their envelope from the

a. cytoplasmic membrane

b. endoplasmic reticulum

c. Golgi membrane complex

d. nuclear membrane


status: not answered ()
correct: a
your answer:


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13 Retroviruses utilize the enzyme ________ to make a DNA copy of their RNA.

a. reverse transcriptase

b. ligase

c. primase

d. DNA polymerase


status: not answered ()
correct: a
your answer:


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14 DNA viruses undergo maturation in the hosts

a. neither nucleus NOR cytoplasm

b. both nucleus AND cytoplasm

c. nucleus

d. cytoplasm


status: not answered ()
correct: c
your answer:


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15 Cellular transformation of host cells may be brought about by

a. proviral integration

b. both proviral integration AND expression of proviral genes

c. expression of proviral genes

d. neither proviral integration NOR expression of proviral genes


status: not answered ()
correct: b
your answer:


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16 The smallest known pathogens that cause plant disease

a. satellites

b. viroids

c. prions

d. deltavirus


status: not answered ()
correct: c
your answer:


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17 Infectious proteins

a. prions

b. deltavirus

c. viroids

d. satellites


status: not answered ()
correct: c
your answer:


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18 Viruses attach to a surface component on the host cell called a(n)

a. receptor

b. phage

c. spike

d. capsid


status: not answered ()
correct: c
your answer:


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19 Cell cultures which can be subcultured indefinitely are called

a. none of these choices

b. cell lines

c. primary cultures

d. standard cultures


status: not answered ()
correct: c
your answer:


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20 Viruses which exist as unintegrated plasmids-like nucleic acid.

a. none of these choices

b. virion

c. provirus

d. episome


status: not answered ()
correct: a
your answer:


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21 Morphological forms of nucleocapsids include

a. complex

b. helical

c. all of these choices

d. cubic


status: not answered ()
correct: c
your answer:


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22 RNA containing viruses assemble in the

a. nucleus

b. neither cytoplasm NOR nucleus

c. both cytoplasm AND nucleus

d. cytoplasm


status: not answered ()
correct: d
your answer:


--------------------------------------------------------------------------------
23
Viruses enter the host cell via

a. viropexis

b. both viropexis AND membrane fusion

c. membrane fusion

d. neither viropexis NOR membrane fusion


status: not answered ()
correct: b
your answer: