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