Micro quiz #2
Intermediate Host
Organism in which a parasite undergoes asexual reproduction or is found only in its immature form.
Definitive Host
Organism in which a parasite undergoes sexual reproduction or matures to its adult form.
Saprophyte
Organism that takes in nutrients from dead and decaying matter.
Chemolithotrophs
Organisms that harvest energy by oxidizing inorganic chemicals.
Chemoorganotrophs
Organisms that harvest energy by oxidizing organic chemicals.
Anoxygenic Phototrophs
Photosynthetic organisms that do not produce O2.
Oxygenic Phototrophs
Photosynthetic organisms that produce O2.
what is a nucleic acid amplification test (NAAT)?
Polymerase chain reaction
Serological typing
Proteins and carbohydrates that vary among strains can be used to differentiate strains. A group of strains that have a characteristic serological type is called a serovar or a serotype.
Serological Testing
Proteins and polysaccharides that make up a prokaryote's surface are sometimes characteristic enough to be identifying markers.
Medical Importance of Protozoa
Protozoa cause diseases such as malaria, African sleeping sickness (trypanosomiasis), and amebiasis.
Structure of Protozoa
Protozoa lack a cell wall, but most maintain a definite shape using the material lying just beneath the cytoplasmic membrane.
Chlamydophila psittaci causes
Psittacosis
reverse transcriptase is a(n) ______ polymerase
RNA-dependent DNA
replicases are _______ polymerases
RNA-dependent RNA
classification
The process of arranging organisms into similar or related groups (taxa), primarily to make it easier to identify them for study.
Classification
The process of arranging organisms into similar or related groups, primarily to make it easier to identify them for study.
Identification
The process of characterizing an isolate (a population of cells descended from a single cell) to determine the group (taxon) to which it belongs
Identification
The process of characterizing an isolate in order to determine the group (taxon) to which it belongs.
Taxonomy
The science of characterizing organisms in order to arrange them into hierarchical groups (taxa); involves three interrelated areas: identification, classification, and nomenclature.
Microscopic Morphology
The size, shape, and staining characteristics of a microorganism yield important clues as to its identity
Strategies Used to Identify Microorganisms
To characterize and identify microorganisms, a wide assortment of technologies is used, including microscopic examination, cultural characteristics, biochemical tests, and nucleic acid analysis.
Molecular Typing
Two isolates that have different restriction fragment length polymorphisms (RFLPs) are considered different strains (figure 10.10). Whole-genome sequencing (WGS) can now be done to compare isolates.
Types of Algae
Types of algae differ in their major photosynthetic pigments, but all contain chlorophyll a.
Yeasts
Unicellular fungi without motile sex cells.
Protists
Usually single-celled eukaryotes that are not fungi, plants, or animals.
Productive Infection
Viral infection in which more viral particles are produced.
Latent Infection
Viral infection in which the viral genome is present but not active, so new viral particles are not being produced.
Lytic Infection
Viral infection of a host cell with a subsequent production of more viral particles and lysis of the cell.
common terms that indicate morphological forms of fungi
Yeasts, mold, and mushroom
Methanogens
are a group of archaea that generate ATP by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor. Their name is derived from the fact that this process generates methane (CH4), a colorless, odorless, flammable gas: 4 H2(energy source)+CO2(terminal electronacceptor)→CH4+2 H2O
what does the nucleotide sequence of ribosomal RNA (rRNA) do?
can be used to identify prokaryotes. Newer techniques simply sequence rDNA. Organisms that cannot yet be cultivated can be identified by amplifying, cloning, and then sequencing specific regions of rDNA.
fungi associate with _______ to form lichens
cyanobacteria and algae
Azotobacter species form
cysts
the normal habitat of bactericides species in humans includes the
genital tract, intestines, genital tract
for the specific name Staphylococcus has which designation?
genus
the molecules that viral spikes attach to on the host cell in order to gain entry are typically ________
glycoproteins
fungal diseases of crops impose a substantial economic burden due to crop damage and expenditures on preventative measures. particularly vulnerable to fungal spoilage are _________, which constitute a large portion of our food supply
grains
The green bacteria are typically
green or brownish. Their accessory pigments are often located in chlorosomes.
an organism that requires a minimum of 9% NaCl would be called an extreme
halophile
morphological features of pseudomonas aeruginosa
has a distinct fruity odor; often produces a soluble greenish pigment
a specialized structure that parasitic fungi use to protrude into host cells is called __________
haustoria
an important trait of species of the thermophilic thermus is their
heat-stable enzymes
Deinococcus species have the ability to withstand
high doses of radiation
Fungal filaments are called
hyphae
Taxonomy consists of three interrelated areas. what are they?
identification, classification, and nomenclature.
members of the genus vibrio
include pathogens such as v. cholorae and v. vulnificus
what does the Nucleic acid amplification tests (NAATs) do?
increase the number of copies of a specific nucleotide sequence, thereby determining if a given organism is present.
how does bacteriophage nucleic acid enter the host cell?
injection
lysogeny is best described as
integration of the viral genome into the host chromosome
directs the incorporation of phage DNA into a bacterial chromosome
intergrase
When hydrogen peroxide is placed on a colony of an unknown bacterium, bubbles form. Based on this information, you can conclude that the bacterium is Staphylococcus epidermidis. is a lactic acid bacterium. is beta-hemolytic. is catalase-positive. can cause strep throat.
is catalase-positive.
productive infection
new viral particles are produced
Thioploca species "commute" to
nitrate-rich waters
Nitrite oxidizers convert
nitrite to nitrate
the process of converting nitrogen gas (N2) to ammonia, which can then be incorporated into cell material, called
nitrogen fixation
one of the early proteins expressed in the T4 lytic cycle is an enzyme called a ______ that degrades the bacterial DNA
nuclease
most animal DNA viruses replicate within the hosts cell's ____
nucleus
the primary defining characteristics of eukaryotes is that they possess a membrane-bound _________
nucleus
a reason why environments that are routinely exposed to O2 can support anaerobic growth is that _________
o2 consuming organisms depletes the oxygen levels
unicellular algae and other free-floating photosynthetic organisms the form the base of the food chain are known as the ______
phytoplankton
Agrobacterium species cause
plant tumors
five kingdom system
plantae, Animalia, fungi, protista (mostly single-celled eukaryotes), and prokaryotae
members of the genus corynebacterium are gram-positive rods that exhibit a variety of shapes. the difference in shape is referred to as being_____
pleomorphic
lichens are good indicators of air quality because _______
polluted air is lethal to them
micrococcus species are gram-_____cocci
positive
Bdellovibrio species
prey on other bacteria Certain species of bioluminescent bacteria form symbiotic relationships with specific types of squid and fish
______ are the causative agents of transmissible spongiform encephalopathies
prions
Bacteria and archaea are given names according to a set of internationally recognized rules called
the International Code of Nomenclature of Bacteria
Bacteria are given names according to an official set of internationally recognized rules:
the international code of nomenclature of bacteria
Epulopiscium species live within
the intestinal tract of surgeonfish.
cyanobacteria harvest the light of ______, using it to convert CO2 into organic compounds
the sun
Nitrogen-fixing cyanobacteria are important ecologically, because
they provide an available source of both carbon and nitrogen -Filamentous species maintain the structure and productivity of some soils. Some species of cyanobacteria produce toxins that can be deadly to animals that ingest contaminated water.
Coxiella burnetii survives well outside the host due
to spore-like structures
properties that are representative of members of Bacteria
-Fatty acids linked to glycerol by ester linkage -peptidoglycan cell wall -no membrane bound nucleus -no introns -70S ribosomes
Detecting Specific Nucleotide Sequences
A probe complementary to a sequence unique to a given microbe is used to detect that organism (figure 10.8). Nucleic acid amplification tests (NAATs) such as PCR increase the number of copies of a specific nucleotide sequence, thereby determining if a given organism is present.
Strain
A pure culture isolate; subgroup within a species.
on what general principle do commercial variations of traditional biochemical tests operate?
A series of tiny wells containing different media are inoculated; metabolic activities yield a pattern of color changes used for identification
Bacteriophage
A virus that infects bacteria; often shortened to phage.
Helminth
A worm; parasitic helminths often have complex life cycles.
If the GC content of two organisms is 70%, the organisms are definitely related. organisms are definitely not related. AT content is 30%. organisms likely have extensive DNA homology. organisms likely have many characteristics in common.
AT content is 30%.
Biochemical typing
Biochemical tests are most commonly used to identify various species of bacteria, but in some cases they can be used to distinguish different strains. A group of strains that have a characteristic biochemical pattern is called a biovar or a biotype.
Algae
Eukaryotic photosynthetic organisms with relatively simple reproductive structures and no organized vascular system.
Phylogeny
Evolutionary relatedness of organisms.
Myxobacteria
Gram-negative bacteria that form complex multicellular structures called fruiting bodies.
Prosthecate Bacteria
Gram-negative bacteria that have extensions projecting from the cells, thereby increasing their surface area.
Sulfur-Oxidizing Bacteria
Gram-negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, generating sulfuric acid.
Nitrifiers
Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite.
Protozoan Reproduction
Life cycles are often complex and include more than one habitat or host. In some cases, a vegetative trophozoite can develop into a resting cyst. Reproduction is often by binary fission; some reproduce by multiple fissions or schizogony.
Spirochetes
Long, helical bacteria that have flexible cell walls and endoflagella.
Protein Profile
MALDI-TOF MS (matrix assisted laser desorption ionization time of flight mass spectrometry) generates a profile of a colony's proteins and macromolecules, which can be used to identify the organism
the three-domain system of classification is based upon comparisons of _______ made my Carl Woese and colleagues in the late 1970s
Nucleotide sequence of ribosomal RNA
Class
A collection of similar orders.
Kingdom
A collection of similar phyla or divisions.
Genus
A collection of similar species.
Virion
A complete virus in its inert non-replicating form; also referred to as a viral particle.
Species
A group of closely related strains; the basic unit of taxonomy.
Mycosis
Disease caused by fungal infection.
Which of the following is the newest taxonomic unit? Strain Family Order Species Domain
Domain
phylogeny
evolutionary relatedness
morphological features of streptococci
fairly small colonies relative to many other types of bacteria
T/F: Algae are a direct cause of human disease in humans
false
T/F: All non cellular infectious agents are viruses
false
T/F: Scientists now understand the true diversity of microbial life and have determined the relationships between the millions of prokaryotes that exist
false
T/F: enveloped and non-enveloped viruses all mature fully in the cytoplasm of the host cell
false
t/f: when a bacterial culture is infected with a temperate phage, all particles of the phage will lysogenize their host
false
facultative anaerobes can use aerobic respiration if O2 is present, and _______ if O2 is not available
fermentation
Cells of myxobacteria come together to form a
fruiting body, within which the cells become dormant microcysts
which of the following are eukaryotes? -fungi -bacteria -anthropods -algae -multicellular womrs
fungi, anthropoids, algae, multicellular womrs
today, protozoa are defined as being unicellular heterotrophic organisms that are not
fungi, slime molds, water molds
infection with fungi
fungus grows on or in the body, causing mycosis
intoxication with fungi
fungus produces a toxin the person ingests
a visible mass of hyphae is Called
mycelium
mycobacterium species stain poorly because their cell walls contain
mycolic acids
fungi growing in a mutually beneficial relationship with plant roots from associations is called _____
mycorrhizas
Extreme halophiles are found in
salt lakes, soda lakes, and brines used for curing fish
fungi are _______, meaning they absorb nutrients from dead or decaying organic matter
saprophytes
to obtain nutrients, fungi _______
secrete enzymes into the environment to break large molecules into smaller ones they can absorb
to differentiate species in the family enterobacteriaceae, a microbiologist would use
serological tests biochemical tests
properties that are representative of members of Archaea
-Hydrocarbons (not fatty acids) linked to glycerol by ether linkage -no membrane-bound nucleus -no peptidoglycan cell wall -sometimes introns -70s ribosomes
fungi causes illness in three general ways
-Hypersensitivity reaction: The person develops an allergic or asthmatic reaction to the fungal components. -Infection: The fungus grows on or in the human body, causing fungal disease or mycosis. -Intoxication: The fungus produces a toxin that a person ingests.
consequences of the widespread distribution of fungal spores in the air we breathe include _______
-allergies in many people -trigger asthma attacks
what mechanisms do newly assembled viruses use to leave their host cell?
-budding -trigering apoptosis
algae _____
-contain chloroplasts with photosynthesis pigments -can be either unicellular or multicellular
examples of genetically unrelated bacteria that are informally grouped based on certain distinctive characteristics include _____
-endospore-formers -lactic acid bacteria -sulfate reducers
eukaryotes are characterized by
-energy transformation primarily occurring in mitochondria -having a True nucleus -organelles used to compartmentalize cell processes
Methane-generating hyperthermophiles
-grow optimally at 84 degrees celsius and can grow at temperatures as high as 122 degrees celsius -use CO2 as a terminal electron acceptor to generate methane -oxidize H2
what are involved in sexual reproduction of fungi?
-hyphae growing toward each other and fusing -hyphae from two different mating types
Things a microscope can determine about a microorganism
-identify microorganism as prokaryote, fungus, protozoan -identifying size and shape -determining the organism type (yeast, ringworm) in cases when the causative agent is suspected (vaginal secretions, stool samples)
consequences of lisogeny include
-immunity to superinfection -lysogenic conversion
fungi are characterized by
-membranes that contain ergosterol -cell walls that contain chitin
properties that are representative of members of Eukarya
-membrans-bound nucleus -cell membranes that contain fatty acids linked to glycerol by an ester linkage -introns -80S ribosomes -no peptidoglycan cell wall
Family
A collection of similar genera. In prokaryotic nomenclature, the name of the family ends in the suffix -aceae.
Domain
A collection of similar kingdoms. The domain reflects the characteristics of the cells that make up the organism
based on their defining characteristics, members of the family enterobacteriaceae
-possess peritrichous flagella if motile -ferment glucose -are facultative anaerobes
required from synthesis of new virus particles in a host cell
-protein synthesis -genome replication -RNA synthesis
MALTI-TOF mass spectrometry in an important new technology in bacterial identification because it can identify an organism from a colony _______
-rapidly, often in less than 15 minutes -based on the profile of its proteins
microscopic examination is important in the presumptive identification of an organism because it can provide information on the organisms
-size and shape -staining characteristics (e.g. gram stain reactions)
_____ phages have the option of entering the prophage state, while _____phages always burst the host cell shortly after injection
-temperate -lytic
the names of different types of mycoses are often based on _________
-the body part affected and causative agent
enveloped viruses can derive their envelopes from
-the host cytoplasmic membrane -certain host organelles
enveloped viruses can derive their envelopes from ________
-the host cytoplasmic membrane -certain host organelles
why is classifcating fungi based on their reproductive structures difficult?
-the sexual forms of some fungi have never been observed -some fungi are known by two different names- their asexual and sexual forms
some anthropods and worms are included in the study of microscopic eukarya because __________
-they are often carried are transmitted in forms that are microscopic -of their role in human disease
processes that are required for production of virus particles in a host cell?
-translation of viral genes -replication of viral genome -transcription of viral genes
characteristics of members of the genus vibrio
-typically found in marine environments -gram-negative straight or curved rods
Species of Pseudomonas
-use oxygen as a terminal electron acceptor -possess polar flagella
some protozoan species can exist as a trophozoite or as a cyst form. how are these forms best described?
-vegetative or feeding form -resting form
steps of an animal virus infection cycle
1) attachment 2) penetration and uncoating 3) synthesis of viral proteins and replication of the genome 4) assembly 5) release
Domain
A collection of similar kingdoms; there are three domains: Bacteria, Archaea, and Eukarya.
The sequence of which ribosomal genes are most commonly used for establishing phylogenetic relatedness? 5S 16S 23S All of these are commonly used.
16S
Which of the following is best to use for determining the evolutionary relatedness of organisms? Ability to form endospores 16S ribosomal RNA sequence Sugar degradation Motility
16S ribosomal RNA sequence
fungi can survive at ph levels of
2.2-9.6
Lysogen
A bacterium that carries phage DNA (a prophage) integrated into its genome.
Lysogenic Conversion
A change in the properties of a bacterium, conferred by a prophage.
Genus
A collection of related species.
Phylum or Division
A collection of similar classes.
Order
A collection of similar families. In prokaryotic nomenclature, the name of the order ends in the suffix -ales.
Medical Importance of Algae
Algae do not directly cause disease, but produce toxins during algal blooms that are ingested by fish and shellfish. Consumption of these shellfish may result in paralytic shellfish poisoning; cooking does not destroy the toxins.
Viroid
An infectious agent of plants that consists only of RNA.
Prion
An infectious protein that causes a neurodegenerative disease.
Sequence Analysis of Ribosomal Components
Analyzing and comparing the nucleotide sequences of rRNA and, more recently, rDNA has revolutionized the classification of organisms. The amino acid sequences of ribosomal proteins can also be compared.
Arthropod
Animal with an external skeleton and jointed appendages such as an insect or an arachnid; may act as a vector in transmitting disease
Antibiograms
Antibiotic susceptibility patterns can be used to characterize strains.
Antibiograms
Antimicrobial susceptibility patterns can be used to distinguish strains
thought to be the earliest bacterial forms to exist on Earth.
Aquifex and Hydrogenobacter
Methanogens
Archaea that obtain energy by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor, thereby generating methane.
Reproduction in Fungi
Asexual reproduction may occur by a variety of methods. Sexual reproduction may involve fusion of hyphae from different mating types.
Tapeworms (Cestodes)
Cestodes are tapeworms with segmented bodies and hooks to attach to the wall of the intestine (figure 12.18). Most tapeworm infections occur in persons who eat uncooked or undercooked meats.
Phenotypic Methods
Classification schemes that group microorganisms by phenotype have largely been replaced by methods that rely on DNA sequence data.
molecular techniques such as _________ have allowed scientists to determine the phylogeny of microorganisms
DNA sequencing
T/F: Lysogens are more susceptible to reinfection by the same type of phage
False
T/F: The three domain system has always been used as the standard classification system for organisms
False
T/F: enveloped viruses enter the host cell by endocytosis only, while non-enveloped viruses can enter the host cell by fusion or endocytosis
False
Molecular typing
Gel electrophoresis can be used to detect restriction fragment length polymorphisms (RFLPs). Whole-genome sequencing (WGS) is increasingly being used to detect differences.
Which of the following is false? Tropheryma whipplei could be identified before it had been grown in culture. The GC content of DNA can be measured by determining the temperature at which double-stranded DNA melts. Sequence differences between organisms can be used to assess their relatedness. Based on DNA homology studies, members of the genus Shigella should be in the same species as Escherichia coli. Gel electrophoresis is used to determine the serotype of an organism.
Gel electrophoresis is used to determine the serotype of an organism.
Cyanobacteria
Gram-negative oxygenic phototrophs; genetically related to chloroplasts.
Lactic Acid Bacteria
Gram-positive bacteria that generate lactic acid as a major end product of their fermentative metabolism.
Life Cycles and Transmission of Helminths
Helminths can be transmitted by burrowing through the skin, being ingested, or being transmitted through insect bites (figure 12.16). Some helminths have complex life cycles with asexual stages occurring in one or more intermediate hosts and the sexual or adult stage occurring in the definitive host. A human being may be a dead-end host in which the organism cannot complete its life cycle.
Fungus
Heterotrophic eukaryotic organism with a chitinous cell wall.
Protozoa
Heterotrophic protists.
Nomenclature
Microorganisms are assigned names governed by official rules.
Phytoplankton
Microscopic free-floating photosynthetic organisms.
Metabolic Capabilities
Most biochemical tests rely on a pH indicator or chemical reaction that shows a color change when a compound is degraded.
Roundworms (Nematodes)
Most nematodes or roundworms are free-living, but they may cause serious disease such as hookworm disease and ascariasis
Protozoan Habitats
Most protozoa are free-living and are found in marine and fresh water as well as terrestrial environments. They are important decomposers in many ecosystems and are a key part of the food chain.
If an acid-fast bacterium is detected in a clinical sample, then the organism could be Cryptococcus neoformans. Mycobacterium tuberculosis. Neisseria gonorrhoeae. Streptococcus pneumoniae. Streptococcus pyogenes.
Mycobacterium tuberculosis.
Culture Characteristics
Selective and differential media used in the isolation process can provide information that helps identify an organism.
were once considered types of fungi.
Slime molds and water molds
Phage typing
Strains of a given species sometimes differ in their susceptibility to various types of bacteriophages.
Strategies Used to Classify Microorganisms
Taxonomic classification categories are arranged in a hierarchical order, with the species being the basic unit. Taxonomic categories include species, genus, order, class, phylum (or division), kingdom, and domain. Individual strains within a species vary in minor properties
DNA Hybridization
The extent of nucleotide similarity between two organisms can be determined by measuring how completely single strands of their DNA will anneal to each other.
Phage Typing
The susceptibility to various types of bacteriophages can be used to demonstrate strain differences
Nomenclature
The system of assigning names to organisms.
Economic Importance of Fungi
The yeast Saccharomyces cerevisiae is used in the production of beer, wine, and bread. Penicillium and other fungi synthesize antibiotics. Fungi spoil many food products and cause diseases of plants such as Dutch elm disease and coffee rust. Fungi have been useful tools in genetic and biochemical studies.
Hyphomicrobium species divide by forming
a bud at the tip of their single polar prostheca
antibiotics that interfere with peptidoglycan synthesis are ineffective in the treatment of mycoplasma infections because these organisms lack
a cell wall
chlamydia trachoma's causes
a common sexually transmitted disease
Species of Rickettsia, Orientia, and Ehrlichia are spread when
a flea or tick transfers bacteria during a blood meal
The methanogens are
a group of archaea that harvest energy by oxidizing H2, using CO2 as a terminal electron acceptor
Magnetotactic bacteria contain
a string of magnetic crystals that allow them to move up or down in water or sediments to the microaerophilic niches they require.
the catalase test detects a microorganism's _________
ability to break down hydrogen peroxide to form O2 and water
mycobacterium
acid fast and are widespread in nature
Their cell walls are made of cellulose and other commercially important materials such as agar and alginic acid. can be microscopic or macroscopic
algae
a diverse group of photosynthetic organisms
algae
Algal Habitats
algae are found in fresh and salt water as well as in soil. Unicellular algae make up a significant part of the phytoplankton.
Ammonia oxidizers convert
ammonium to nitrite`
while fungal classifications are still changing, four current groups of fungi are _______
ascomycetes (Ascomycota), basidiomycetes (Basidiomycota), zygomycetes (Zygomycota), and chytrids (Chytridiomycota)
Algal Reproduction
asexual and sexual reproduction
During the ______ or maturation step in viral multiplication, capsids and genetic material are packaged into virions
assembly
in which phase of the T4 phage lytic cycle are new phage particles put together
assembly
Chlamydophila pneumonia causes
atypical pneumonia
______ species are gram-negative, strictly anaerobic, make up about a third of the bacteria in fecal matter, and are associated with abscesses and bloodstream infections
bacteroides
species
basic taxonomic unit that is a group of isolates or strains A group of closely related strains. Note that members of a species are not all identical; individual strains may differ from one another. The difficulty for the taxonomist is to decide how different two isolates must be in order to be classified as separate species rather than strains of the same species. In certain cases, a species may be divided into two or more subspecies. This is particularly true for the commercially valuable organisms used to make fermented foods.
A group of strains that has a characteristic biochemical variation is called a
biovar, or a biotype
viral release method that does not initially destroy the cell
budding
the number of phage particles released from a host cell is called the _____ size
burst
nucleic acid amplification tests (NAATs)
can be used to increase the number of copies of specific DNA sequences that serve as identifying markers. This allows researchers to detect the sequences in samples such as body fluids, soil, food, and water. These methods can be used to detect organisms present in extremely small numbers as well as those that cannot yet be grown in culture. In most cases, the amplified fragment is visible as a distinct band when the DNA is separated on an agarose gel, stained, and illuminated with UV light.
Anaerobic Chemoorganotrophs
can obtain energy vie fermentation produce ATP via substrate level phosphorylation
the viral genome is protected from the environment by a protein sheath called the ___
capsid
presence of the enzyme _____ is a key characteristic of staphylococcus species that is used to distinguish them from gram-positive cocci that do not require aerobically, such as streptococcus species
catalase
Streptomyces species form
chains of conidia at the end of hyphae. Many species naturally produce antibiotics
Fungi have_______ cell walls and are often saprophytes, secreting enzymes onto a surface and absorbing nutrients.
chitinous
species in the genus neisseria are ______
cocci, gram-negative, typically found in pairs
asexual reproductive cells of fungi are typically called ________
conidia
Genetic evidence indicates that chloroplasts evolved from a species _____
cyanobacteria
The G + C content can be measured by
determining the temperature at which double-stranded DNA melts
The basic strategy for identification using biochemical tests relies on the use of a ____ ______
dichotomous key
algae with different pigments can live at ______
different depths
a ______fundus is one that can grow as single yeast cells or multicellular hypahe, depending on the environmental conditions
dimorphic
fungi that can grow either as single cells (yeast) or as mycelia.
dimorphic fungi
because the skin is ______, growth of many organisms is prevented
dry and salty
what is a significant limitation of detecting specific nucleotide sequences in order to identify prokaryotes?
each probe or amplification detects only a single possibility, so multiple probes/amplifications may be needed to uniquely identify
a non-enveloped virus can gain entry into animal cells via ___
endocytosis of the virus by the host cell
Spirochetes move by means of
endoflagella
Clostridium species form _______
endospores
Bacillus and Clostridium species form
endospores, the most resistant dormant form known
The lactic acid bacteria produce
lactic acid as their primary fermentation end product Page 307
compared to bacterial endospores, fungal spores are much _________ to environmental conditions
less resistant
result from an association of fungus with a photosynthetic organism such as an alga or a cyanobacterium
lichens
in the laboratory, for quick identification of fungi, it is most practical to ________
look at the asexual reproductive forms
the physical rupture of a cell is termed
lysis
some pathogenic bacteria produce toxins that are encoded on prophage DNA, and these are examples of ______ conversion
lysogenic
____ is a change in the phenotype of a lysogen as a consequence of the specific prophage it carries
lysogenic conversion
If two microbial isolates have similar but different 16S rRNA sequences, they are probably both motile. both pathogens. both cocci. members of the same domain. the same strain.
members of the same domain.
a nuclear division in which each daughter cell receives the same number of chromosomes as the parent cell is _________
mitosis
Fungi prefer to grow in a _____ environment
moist
Bacteroides species inhabit the
mouth, intestinal tract, and genital tract of humans and other animals.
Chemolithotrophs
obtain energy by oxidizing inorganic chemicals such as hydrogen gas (H2) to obtain energy. Those growing anaerobically obviously cannot use O2 as a terminal electron acceptor and instead must use an alternative such as carbon dioxide or sulfur.
morphological features of serratia marcescens
often red when incubated at 22 degrees c
fungi can be found
on many different habitats on earth
a strain is _____
one of a group of related isolates within a species
chemoorganotrophs oxidize ______compounds such as glucoses to obtain energy
organic
Chemoorganotrophs
oxidize organic compounds such as glucose to obtain energy. Those that grow anaerobically often use sulfur or sulfate as a terminal electron acceptor.
humans infected with helicobacter pylori may develop
peptic ulcers
hypersensitive reactions with fungi
person develops an allergic or asthmatic reaction to fungal components
Chlamydia and Chlamydophila species are transmitted directly from
person to person
DNA sequences can be used to construct a
phylogenetic tree
virus infections that result in the formation of new virus particles are described as
productive
nitrogen fixation, or the process of converting nitrogen gas (N2) into ammonia, is an exclusive ability of _______
prokaryotes
RNA viruses have a higher mutation rate than DNA viruses because replicase lacks _____ ability
proofreading
Propionibacterium species produce
propionic acid as their primary fermentation end product.
diverse group of microscopic, unicellular organisms that lack chlorophyll.
protozoa
Legionella species often reside within
protozoa; they can cause respiratory disease when inhaled.
Deinococcus radiodurans can survive
radiation exposure several thousand times that lethal to a human being.
The purple bacteria appear
red, orange, or purple; the components of their photosynthetic apparatus are all within the cytoplasmic membrane.
by defininton, obligate intracellular parasites cannot
replicate outside a host cell
to maintain a lysogenic state, a _______ protein prevents expression of the gene required for excision
repressor
obligate anaerobes obtain energy using
respiration only
HIV is describes as a _______ because it uses reverse transcriptase to make a DNA copy from its RNA genome
retrovirus
The "O157:H7" of E. coli O157:H7 refers to the biotype. serotype. phage type. antibiogram.
serotype.
A group of strains that differs serologically from other strains is called a
serovar, or a serotype
reassortment of gene segments that encode viral surface proteins that are recognized by the immune system can result in a loss of the immune system's ability to recognize and respond to the virus. this phenomenon is called antigenic _______
shift
Caulobacter species have a
single polar prostheca called a stalk; at the tip of the stalk is a holdfast. The cells divide by binary fission
staphylococcus epididymis is found in normal microbiota of the ____
skin
Micrococcus species are found in
soil and on dust particles, inanimate objects, and skin
Sheathed bacteria attach to
solid objects in favorable habitats; the sheath shelters them from attack by predators
both treponema and borrelia are characterized by their corkscrew shape and endoflagella, thus making them
spirochetes
Thiomargarita namibiensis, the largest bacterium known, stores
sulfur and has a nitrate-containing vacuole.
Desulfovibrio species reduce ____ to form ______
sulfur compounds to form hydrogen sulfide
algae abosrb____ to convert
sunlight to convert CO2 and H2O into organic material and O2
after a virus enters a cell, the nucleic acid separates from the protein coat, a process called ______
uncoating
The "breath test" for Helicobacter pylori infection detects the presence of which of the following? Antigens Catalase Hemolysis Lactose fermentation Urease
urease
Arthropods can act as
vectors
latent state
viral genome remains silent within cell
most important for attachment of a virus to a host cell?
viral specificity for host receptors
before enveloped viruses bud from a host cell, specific viral proteins insert into the host membrane. these proteins become ______
viral spikes
A _____ is an infectious agent that lacks a capsid and consists only of RNA
viroid
size smallest to larges
viruses, human cells, bacteria
extreme thermophiles are found
volcanic vents, hot springs, hydrothermal vents
Spirillum volutans form
volutin granules, a storage form of phosphate.
Pseudomonas species are
widespread in nature and have extremely diverse metabolic capabilities
helminths
worms
saccharomyces cerevisiae, commonly used in the baking, wine, and beer industries is a type of single-celled fungus known as _____
yeast
single-celled fungi are
yeast