BIOL 2420 Exam 3

Taxonomy

The science of classifying microorganisms.

Taxa

General term for taxonomic categories.

Taxonomy

Provides universal names for organisms.

Taxonomy

Provides a reference for identifying organisms.

Phylogeny

The study of the evolutionary history of organisms.

1.7 million

Number of identified species of life on Earth.

Eukarya

Domain which includes protists, fungi, animals, and plants.

Bacteria

Domain which includes prokaryotes, most with peptidoglycan in their cell wall.

Archaea

Domain which includes prokaryotes which do not have peptidoglycan; often live in extreme environments (salty, extremely hot).

Common Names

Informal identification of species which varies with languages and geography.

Binomial Nomenclature

Formal, universal identification of species which includes genus and specific epithet.

Kingdom

Each domain includes more than one ______.

Phylum

Each kingdom includes more than one ______.

Class

Each phylum includes more than one ______.

Order

Each class includes more than one ______.

Family

Each order includes more than one ______.

Genus

Each family includes more than one ______.

Species

Each genus includes more than one ______.

Strain

A group of genetically different cells resulting from genetic divergence (mutation) within a clone.

Identified by numbers, letters, or names that follow the specific epithet.

Eukaryotic Species

Generally defined as a group of closely related organisms that breed among themselves.

Prokaryotic Species

A population of cells with similar characteristics.

Animalia

(Eukaryotic Family)

-Multicellular

-No cell walls

-Chemoheterotrophic, ingest food

-Include parasitic worms (helminths)

Plantae

(Eukaryotic Family)

-Multicellular

-Cellulose cell walls

-Usually photoautotrophic

Fungi

(Eukaryotic Family)

-Chemoheterotrophic

-Unicellular or multicellular

-Cell walls of chitin

-Develop from spores or hyphal fragments

-Absorb pre-digested food

Fungi

(Eukaryotic Family)

-Includes molds and yeasts

Protista

(Eukaryotic Family)

Kingdom for eukaryotic organisms that do not fit other kingdoms, such as algae and protozoans.

Viral Species

Population of viruses with similar characteristics that occupies a particular ecological niche.

Classification

Placing organisms in groups of related species.

Lists of characteristics of known organisms.

Identification

Matching characteristics of an "unknown" organism to lists of known organisms.

Morphological Characteristics

(Identification Method)

e.g.

-Shape

-Arrangement

-Presence of flagella

-Presence of endospores

Differential Staining

(Identification Method)

e.g.

-Gram staining

-Acid-fast staining

Biochemical Tests

(Identification Method)

Determines presence of bacterial enzymes.

Selective and/or differential media.

e.g.

-metabolize lactose

-produce acid or gas during metabolism

Serology

The science that studies serum and immune responses that are evident in serum (presence of antibodies).

Serum

The liquid remaining after blood plasma is clotted; contains antibodies.

Antiserum

A solution of specific antibodies.

Slide Agglutination Test

Known antiserums are mixed with the unknown bacteria.

If the antiserum contains antibodies that are made to react with the bacteria, clumping (agglutination) will occur and indicate a positive test.

Phage Typing

Determines which phages a bacterium is susceptible to.

Bacteriophages form "plaques", or areas of lysis, on a plate if bacteria is susceptible.

DNA base composition

(Genetic identification method)

Guanine + cytosine % (GC).

Each species contains specific unique sequences.

DNA fingerprinting

(Genetic identification method)

Electrophoresis of restriction enzyme digests.

Each species reveals specific unique banding patterns.

Proteobacteria

Largest taxonomic group of bacteria.

Proteobacteria

All bacteria in this group are gram negative.

Share a particular rRNA sequence

Represent all four modes of nutrition.

Proteobacteria

Taxonomic group of bacteria which includes E. coli.

Proteobacteria

Taxonomic group of bacteria which includes Vibrio cholerae.

Vibrio cholerae

Species of proteobacteria which causes cholera.

Vibrio cholerae

Species of proteobacteria which is spread from contaminated water and food.

Causes severe diarrhea, vomiting, and dehydration.

Thiomargarita namibiensis

Species of proteobacteria which uses hydrogen sulfide to generate organic molecules from carbon dioxide.

Produced sulfur wastes, seen as small greenish globules.

Rhizobium

Genus of proteobacteria which live symbiotically in root nodules of legumes.

Convert atmospheric nitrogen gas into a form usable by their legume host.

Nitrogen Fixation

Conversion of atmospheric nitrogen gas into a usable form.

Endosymbiosis

Refers to one species, called the endosymbiont, living symbiotically within another.

Endosymbiont

Rhizobium is an ______, meaning it lives symbiotically within another species.

Neisseria gonorrhoeae

Proteobacteria which causes gonorrhea.

Gonorrhea

STD caused by Neisseria gonorrhoeae.

Cyanobacteria

Gram-negative, the only group of prokaryotes with plantlike, oxygen-generating photosynthesis.

Some species, such as Anabaena, have specialized cells that fix nitrogen.

Chlamydias

Gram-negative group of bacteria which live inside eukaryotic host cells.

Trachoma

An infection of the eye that causes blindness in developing countries, caused by Chlamydia trachomatis.

Chlamydia trachomatis

Species which causes trachoma and nongonococcal urethritis.

Spirochetes

Gram-negative, helical bacteria with axial filaments used for movement.

Spirochetes

Group of bacteria which includes Treponema pallidum and Borrelia.

Treponema pallidum

Species of spirochete which causes syphilis.

Syphilis

Caused by Treponema pallidum.

Characterized in its primary stage by genital sores. If untreated, can develop much more serious and fatal symptoms.

Borrelia

Genus of spirochetes which cause Lyme disease.

Lyme disease

Caused by Borrelia.

Transmitted by ticks and characterized initially by a rash followed by flu-like symptoms including fever, joint pain, and headache.

Gram-positive bacteria

Group of bacteria which includes:

-actinomycetes common in soil as organic matter decomposers.

-streptomyces often cultured as a source of antibiotics (streptomycin).

Gram-positive bacteria

Group of bacteria which includes:

Staphylococcus

Streptococcus

Bacillus anthracis

Eukaryotes

Fungi, Algae, Protozoa, and Helminths

Mycology

The study of fungi.

100,000

There are approximately ______ known species of fungi.

Macroscopic Fungal Forms

Group of fungi which includes multicellular such as mushrooms, puffballs, gill fungi—mushrooms with gills under their caps.

Microscopic Fungal Forms

Group of fungi which includes molds and fleshy fungi made of filamentous hyphae, and yeasts.

Molds

A morphology of microscopic fungal forms. Consist of hyphae.

Hyphae

Long filaments of cells, or "cell-like units," joined together to form molds.

Yeasts

A morphology of microscopic fungal forms. Unicellular fungi; round oval shape.

Fungi

Taxonomic kingdom which includes fungi.

Chemoheterotroph

Nutritional type, fungi.

Chitin

The cell walls of fungi are made of ______.

Budding Yeasts

Yeasts which reproduce by asymmetrical division.

Fission Yeasts

Yeasts which reproduce by symmetrical division.

Pseudohypha

Chain of budding yeast cells.

Yeasts

Type of fungi which form colonies with soft, uniform texture and appearance (much like bacterial colonies).

Mycelium

Mass of hyphae.

Dimorphic

Fungi which alternate between yeastlike and moldlike forms depending on growth conditions (i.e. temperature).

Particularly characteristic of some pathogenic molds.

Heterotrophic

All fungi are ______, meaning they do not make their own food; obtain nutrition from outside source.

Substrate

Fungi obtain nutrients from a ______, a surface on or in which the organism lives and uses as a source of food.

Rhizoids

Some species of fungi grow ______, structures that anchor them to the substrate.

Saprobes

The majority of fungi are harmless ______, living off dead plants and animals; thus play a role as decomposers of dead material.

Obligate

Some fungi are parasites, living on the tissues of other organisms, but few are ______.

Mycoses

Fungal infections in animals.

Septa

Hyphae may be divided by cross walls called ______.

Porous Septate Hyphae

Hyphae with holes in septa, allowing flow of organelles and nutrients between adjacent compartments.

Nonporous Septate Hyphae

Hypae which contain septa without holes through them.

Coenocytic Hyphae

Hyphae which have continuous cytoplasmic flow, either due to no septa, or porous septa.

Vegetative Hyphae

Hyphae which digest and absorb nutrients.

Reproductive Hyphae

Hyphae which branch off vegetative hyphae and produce spores for reproduction.

Reproductive Hyphae

Also known as "aerial hyphae."

Thallus

Term referring to the body or assimilative structure of a fungus, which could be yeast-like or mold-like.

Fragmentation

Fungal asexual reproduction method in which a separated piece of mycelium forms a whole new colony of hyphae

Conidiospores

Type of asexual fungal spores.

Free, not contained in sacs; break off of hyphae.

aka "conidia."

Sporangiospores

Type of asexual fungal spores.

Develop and contained in sacs called sporangia, which ruptures and releases spores.

Zygospore

Type of sexual spore in fungi.

Germinates and forms a mycelium, which gives rise to a zygosporangium that produces sporangiospores by meiosis, thus are genetically different from the parent strains.

Ascospore

Type of sexual spore in fungi.

Male and female organs fuse to form a special sac called an ascus, in which the spores are produced.