Chapter 1 (terms) Flashcards
1
Q
is the study of microorganisms,
A
Microbiology
2
Q
a large and diverse
group of microscopic organisms that exist as single cells or cell
clusters; it also includes viruses,
A
microorganisms,
3
Q
one test of the merit of a scientific hypothesis
A
originality
4
Q
a useful hypothesis should provide a basis for
A
generalization
5
Q
the practical outgrowth of science, is a product created by a blend of technique and theory
A
prediction
6
Q
provide the tools for analysis of microorganisms
A
biochemistry, molecular biology, genetics
7
Q
extends the horizons of these scientific disciplines
A
microbiology
8
Q
one that benefits all of the contributing parties
A
mutualism
9
Q
example of microbial mutualism
A
lichen
10
Q
consists of fungus and phototrophic partner
A
lichens
11
Q
mutualism in biology is
A
symbiosis
12
Q
benefit of one party
A
parasitism
13
Q
host provides the primary benefit to the parasite
A
parasitism
14
Q
terms that relate to the science of ecology
A
mutualism, symbiosis, parasitism
15
Q
are implicit in microbiology
A
principles of environmental biology
16
Q
products of evolution, biologic consequence of natural selection
A
microorganisms
17
Q
groups of eukaryotic microorganisms
A
algae, protozoa, fungi, slime molds
18
Q
viruses lack attributes of a cell including
A
ability to replicate
19
Q
acquire the key attribute of a living system -
A
reproduction when they infect a cell
20
Q
infect other viruses
A
virophages
21
Q
tend to be
highly specific, and the biologic range of viruses mirrors the
diversity of potential host cells.
A
Host–virus interactions
22
Q
are generally small (eg, adenovirus
is 90 nm) and consist of a nucleic acid molecule, either
DNA or RNA, enclosed in a protein coat, or capsid (some-
times itself enclosed by an envelope of lipids, proteins, and
carbohydrates).
A
Viral particles
23
Q
adenovirus
is
A
90nm
24
Q
glycoproteins—in the
capsid determine the specificity of interaction of a virus
with its host cell.
A
Proteins—frequently glycoproteins—
25
protects the nucleic acid and
facilitates attachment and penetration of the host cell by the
virus.
capsid
26
consists of assembling newly synthesized nucleic acid
and protein subunits into mature viral particles, which are
then liberated into the extracellular environment.
Maturation
27
also known as
| hepatitis D virus,
delta agent
28
is too small to code for even a single capsid
protein and needs help from hepatitis B virus for transmis-
sion.
hepatitis D virus
29
are known to infect a wide variety of plant and
animal hosts as well as protists, fungi, and bacteria.
Viruses
30
a DNA virus infecting Acanthamoeba,
Mimivirus
31
a free-
living soil ameba, has a diameter of 400–500 nm and a
genome that encodes 979 proteins, including the first four
aminoacyl tRNA synthetases ever found outside of cellular
organisms and enzymes for polysaccharide biosynthesis.
Acanthamoeba
32
An even larger marine virus has recently been discovered
Megavirus
33
A number of transmissible plant diseases are caused
by
viroids
34
—small, single-stranded, covalently closed circular RNA molecules existing as highly base-paired rodlike
structures.
viroids
35
a degenerative central
| nervous system disease of sheep.
scrapie
36
was introduced to emphasize its proteinaceous and infectious nature.
prion
37
extracellular form of the viroid is
naked RNA - no capsid of any kind
38
cellular form prion is
encoded by the host's chromosomal DNA
39
is a sialoglycoprotein with a molec-
ular mass of 33,000–35,000 Da and a high content of α-helical secondary structure that is sensitive to proteases and soluble
in detergent.
PrP^c
40
is expressed on the surface of neurons via a glycosylphosphatidyl inositol anchor in both infected and
uninfected brains.
PrP^c
41
PrPc is expressed on the surface of neurons via
glycosylphosphatidyl inositol anchor
42
occurs in the prion protein, changing it from its normal or cellular form PrP^c to the disease-causing conformation, PrP^Sc
conformational change
43
There are additional prion diseases of importance
Kuru, Creutzfeldt-Jakob dis-
| ease (CJD), Gerstmann-Sträussler-Scheinker disease, and fatal familial insomnia
44
which is thought to result from the ingestion
of feeds and bone meal prepared from rendered sheep offal,
has been responsible for the deaths of more than 184,000
cattle in Great Britain since its discovery in 1985.
Bovine spongiform encephalopathy
45
has been associated with human ingestion of prion-infected beef in the United Kingdom and France.
A new variant of CJD (vCJD)
46
as a consequence of infection sialoglycoprotein is converted to
protease-resistant form
47
are unique in that they manifest
| as sporadic, genetic, and infectious diseases.
human prion diseases
48
the cell containing DNA is termed the
nucleoid
49
are their relatively small size, usually on the order of 1 μm in diameter, and the absence of a nuclear membrane.
prokaryotes
50
The DNA of almost all bacteria is a circle with a length of about 1 mm; this is the
prokaryotic chromosome.
51
Recent data
based on genome sequencing indicate that the number of
genes within a prokaryote may vary from 468 in
Mycoplasma genitalium
52
Recent data based on genome sequencing indicate that the number of genes within a prokaryote may vary from 468 in Mycoplasma genitalium to 7825 in
Streptomyces coelicolor
53
Recent data
based on genome sequencing indicate that the number of
genes within a prokaryote may vary from 468 in Mycoplasma
genitalium to 7825 in Streptomyces coelicolor, and many of
these genes must be dedicated to essential functions such as
energy generation, macromolecular synthesis, and cellular replication.
54
is the chief source of energy for life.
Light from the sun
55
what prokaryote convert light energy to metabolic energy in the absence of oxygen production?
purple bacteria
56
prokaryote that produce oxygen that can provide energy through respiration in the absence of light
blue-green bacteria (Cyanobacteria)
57
these organisms depend on respiration w/oxygen for energy
Aerobic organisms
58
some of these organisms can use electron acceptors other than oxygen in respiration
anaerobic organisms
59
these are carried out in which energy is derived by metabolic rearrangement of chemical growth substrates
fermentations
60
this means arrangements in w/c the physiologic characteristics of dif. org. contribute to survival of the group as a whole
consortia
61
wellspring of the evolutionary process called
natural selection
62
within clones it is likely to provide physiologic protection to at least some members of the group
high number of cells
63
they may afford protection against potentially lethal agents such as antibiotics/heavy metal ions
extracellular polysaccharides
64
cell-cell communication mechanism called
quorum sensing
65
this is exploited by many bacteria to regulate the transcription of genes involved in diverse physiologic processes (bioluminescence, plasmid conjugal transfer & production of virulence determinants)
quorum sensing
66
Examples of diverse physiologic processes included in the transcription of genes
bioluminescence, plasmid conjugal transfer, production of virulence determinants
67
it depends on the production of one or more diffusable signal molecules (acetylated homoserine lactone - AHL) termed autoinducers or pheromones that enable a bacterium to monitor its own cell population density
quorum sensing
68
an example of diffusable signal molecules termed autoinducers or pheromones
acetyl homoserine lactone (AHL)
69
this enable a bacterium to monitor its own cell population density
autoinducers/pheromones
70
the cooperative activities that lead to a formation called _____ are controlled by quorum sensing
biofilm formation
71
it is an ex of multicellular behavior in prokaryotes
the cooperative activities leading to biofilm formation are controlled by quorum sensing
72
it is a distinguishing characteristic of prokaryotes
capacity to exchange small packets of genetic information
73
these are small and specialized genetic elements that are capable of replication w/in at least one prokaryotic cell line, and they may carry small packets of genetic info.
plasmids
74
these may be transferred from one cell to another and thus may carry sets of specialized genetic info through a population
plasmids
75
some plasmids exhibit ________ that allows them to convey sets of genes to diverse organisms
broad host range
76
these plasmids may render diverse bacteria resistant to antibiotic treatment
drug resistance plasmids
77
this can lead to loss of functions that may not allow growth of the symbiont/parasite independent of its host
advanced symbiosis/parasitism
78
are parasitic prokary-
| otes that have lost the ability to form a cell wall.
mycoplasmas
79
not found in other prokaryotes, is assimilated from the metabolic envi-
ronment provided by the host.
Cholesterol
80
Loss of function is exemplified
also by
obligate intracellular parasites (e.g. chlamydiae & rickettsiae)
81
These bacteria are extremely small (0.2–0.5 μm
in diameter) and depend on the host cell for many essential
metabolites and coenzymes.
chlamydiae and
| rickettsiae.
82
The most widely distributed examples of bacterial symbi-
| onts appear to be
chloroplasts and mitochondria
83
prokaryotes that established sym-
| biosis within the cell membrane of the ancestral eukaryotic host.
endosymbionts
84
ancestors of chloroplasts and mitochondria are
endosymbionts
85
An understanding of any group of organisms requires their
classification
86
allows prediction of many additional traits
shared by other members of the category.
categorization
87
may also provide a broad understanding of relationships
among different organisms, and such information may have
great practical value.
classification
88
elimination of a patho-
| genic organism will be relatively long-lasting if its habitat is occupied by a
nonpathogenic variant
89
At the outset, it should be recognized that any
prokaryotic characteristic might serve as a potential criterion for classification. However, not all criteria are equally effective in grouping organisms. Useful criteria may be
structural, physiologic, biochemical,
| or genetic.
90
Spores—specialized cell structures that may
allow survival in extreme environments—are useful structural criteria for classification because well-characterized subsets of bacteria form this
Spores
91
Some bacterial groups can
be effectively subdivided on the basis of their ability to _____specified carbohydrates.
ferment
92
is an effective criterion for classification because response to the stain reflects fundamental and complex differences in the bacterial cell surface that divide most bacteria into two major groups.
Gram stain
93
are increasingly used in bacterial classification, and many of these advances are made possible by the development of ____
Genetic criteria, DNA-based technologies
94
DNA probe or DNA amplification assays examples
polymerase chain reaction [PCR] assays)
95
these are now possible to design to swiftly identify organisms carrying specified genetic regions with
common ancestry.
DNA probe or DNA amplification assays
96
Comparison of DNA sequences for some
| genes led to the elucidation of ______ among prokaryotes
phylogenetic relationships
97
Ancestral cell lines can be traced, and
organisms can be grouped on the basis of their
evolutionary affinities.
98
comparison of this sequence suggests that all eukaryotes, including humans, arose from one of three different groups of purple photosynthetic bacteria.
cytochrome c sequences
99
comparison of cytochrome c
sequences suggests that all eukaryotes, including humans, arose from one of three different groups of _____
purple photosynthetic bacteria.
100
two major groups of prokaryotes
bacteria & archaebacteria
101
they carry out an anaerobic respiration
that gives rise to methane,
methanogens
102
they demand extremely
high salt concentrations for growth,
halophiles
103
they require high temperature and acidity.
thermoacidophiles
104
An intriguing trait shared by archaebacteria and eukaryotes is the presence of ___ w/in genes
introns
105
represent a fundamental characteristic shared
| by the DNA of archaebacteria and eukaryotes.
introns
106
these are evolutionary derivatives of bacteria
chloroplasts & mitochondria
107
this may have risen from an archaebacterial ancestor
eukaryotic nucleus
108
The agents of
| motility for eukaryotic cells are
flagella or cilia
109
"true nucleus" is only one of their distinguishing features.
eukaryotes
110
it is a highly specific event and establishes the basis for eukaryotic species
fusion of gametes to form reproductive progeny
111
prokaryotes exchange fragments of DNA through
recombination
112
Taxonomic groupings of eukaryotes frequently are based on shared
morphologic properties
113
microbial eukaryotes ______ are members of the 4 ff. major groups: algae, protozoa, fungi, slime molds
protists
114
has long been used to denote all organisms
| that produce O2 as a product of photosynthesis.
algae
115
One major
| subgroup of these organisms—the ____ are prokaryotic and no longer termed algae
blue-green bacteria (cyanobacteria)
116
All algae contain______in the photosynthetic membrane of their subcellular chlo-
roplast.
chlorophyll
117
what algae sometimes are several hundred meters in length.
Kelps of brown algae
118
a unicellular alga, cause algal blooms, or red tides, in the ocean
Dinoflagellates
119
Red tides caused by the _______are serious because this organism produces neurotoxins such as ____________
dinoflagellate Gonyaulax species, saxitoxin and gonyautoxins,
120
Ingestion of these shellfish by humans results in symptoms of
paralytic shellfish poisoning and can lead to death.
121
are unicellular nonphotosynthetic protists.
Protozoa
122
It seems likely that the ancestors of these protozoa were algae that became
heterotrophs
123
the nutritional requirements of such organisms are met by organic compounds.
heterotrophs
124
(characteristic of the ameba)
pseudopodia
125
A fourth major group of protozoa, the ______
sporozoa
126
are strict parasites that are usually immobile; most of these reproduce sexually and asexually in alternate generations by means of spores
sporozoa
127
are nonphotosynthetic protists growing as a mass
of branching, interlacing filaments (“hyphae”) known as a
mycelium.
fungi
128
The fungi are nonphotosynthetic protists growing as a mass of branching, interlacing filaments (“hyphae”) known as a
mycelium
129
(a multinucleated mass of continuous cytoplasm)
coenocyte
130
The mycelial forms are called
molds
131
they do not form a mycelium but are easily recognized as fungi by the nature of their sexual reproductive processes and by the presence of transitional forms.
yeasts
132
probably represent an evolutionary offshoot of
| the protozoa; they are unrelated to the actinomycetes, mycelial bacteria that they superficially resemble.
fungi
133
The major sub-divisions (phyla) of fungi are
Chytridiomycota, Zygomycota (the zygomycetes), Ascomycota (the ascomycetes), Basidiomycota (the basidiomycetes), and the “deuteromycetes” (or imperfect fungi).
134
ascomycetes evolved from the _____
phycomycetes
135
The evolution of the ascomycetes from the phycomycetes is seen in a transitional group, whose members form a zygote but then transform this directly into an ____
ascus
136
are believed to have evolved in turn from the
ascomycetes.
basidiomycetes
137
These organisms are characterized by the presence, as a stage in their life cycle, of an ameboid multinucleate mass of cytoplasm called a
plasmodium
138
interlacing filaments
hyphae
139
is analogous to the mycelium of a true fungus.
plasmodium of a slime mold
140
both are coenocytic
fungi, slime molds
141
Reproduction of the slime molds via
plasmodia
142
Reproduction of the slime molds via plasmodia can depend on
intercellular recognition and fusion of cells from the same species.
