Taxonomy - Eukaryotes Flashcards by Olivia Pouret

What is used to infer the phylogeny of eukaryotes?

Sequencing of 18S rRNA genes

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Relationship between 18S rRNA genes is ___ for eukaryotes than 16S rRNA genes is for prokaryotes.

weaker

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How is phylogeny determined?

by MLST

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Green algae are also called ____.

chlorophytes

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Red algae are also called _____.

rhodophytes

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Most green algae inhabit _____.

freshwater

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Most red algae inhabit _____.

marine water

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The red colour of red algae is from _____ which is produced in abundance in deep water.

phycoerythrin (an accessory pigment)

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Most red algae are ____.

multicellular

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What is Galdieria?

a unicellular red algae that lives in acidic hot springs

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Which algae grows inside pours rocks?

Endolithic algae (green)

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Which endosymbiosis involves red/green algae?

Secondary endosymbiosis

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What is primary endosymbiosis?

When cell from cyanobacteria in lineage of bacteria enters a eukaryotic cell. It is followed by secondary endosymbiosis

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What are diplomonads and parabasalids? what are their characteristics?

They are protists

unicellular
flagellated
lack chloroplasts
live in ANOXIC habitats

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What is the key genera of diplomonads? and their characteristics?

Giardia

have 2 nuclei the same size
have MITOSOMES

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What is a mitosome?

a reduced form mitochondrion (doesn’t have enzymes of the TCA and doesn’t have respiratory chain), they are involved in the maturation of ion-sulfur clusters

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What is the key genera of parabasalids? and their characteristics?

Trichomonas

contain a parabasal body
lack mitochondrion but have HYDROGENOSOMES for anaerobic metabolism
live in intestinal and urogenital tracts

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What is a hydrogenosome?

an organelle, oxidation of pyruvate to H2, CO2 and acetate which is found in some protozoan whose metabolism is STRICTLY FERMENTATIVE

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What is an amitochondriate eukaryote?

a eukaryote that lacks a mitochondria.

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____ protect the cells against deleterious environmental conditions.

Cysts

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Cysts are similar to _____ produced by prokaryotes. They survive long periods of starvation/desiccation

endospores

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Euglenozoans are _______

unicellular flagellated eukaryotes

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Kinetoplastids have a _____. They live primarily in ______ habitats and feed on _____

kinetoplast; aquatic; bacteria

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What is a kinetoplast?

a mass of circular DNA present in their single large mitochondrion

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Give an example of kinetoplastid and what it is.

Trypanosoma brucei: sleeping sickness, lives/grows in blood stream, infects central nervous system, tsetse fly transmits is

Euglenids and kinetoplastids are a sub-category of ____

euglenozoans

Euglenids have ____

chloroplasts

Stalked mother cell produces 2 morphologically distinct progeny which are?

- daughter swarm cell: has flagellum (can't reproduce at first then become early stalk) - daughter non-motile stalk cell

What characterizes alveolates?

the presence of alveoli which are sacs underneath the cytoplasmic membrane

Function of alveoli?

maintain osmotic pressure

What are the three sub-categories of alveolates?

- ciliates (paramecium which have a contractile vacuole) - dinoflagellates (have 2 flagella) - apicomplexans

What are cilia used for?

used fo motility and to obtain food

What is a characteristic of ciliates?

they have 2 nuclei: | macronucleus and micronucleus

During conjugation (sexual reproduction) 2 paramecia exchange _____.

micronuclei

Some ciliates are animal ____ and some are animal ____ (in the rumen)

parasites; symbionts

Dinoflagellates are diverse marine and freshwater ______ organisms.

phototrophic

What are the two types of flagella in dinoflagellates?

- transverse flagellum | - longitudinal flagellum

Some species of dinoflagellates secrete ____.

neurotoxins

Dense suspension of dinoflagellates are called _____.

red tides

What happens if you ingest toxic dinoflagellates?

human poisoning -> paralytic shellfish poisoning.

Apicomplexans are ______ parasites of animals.

obligate

What is the life cycle of apicomplexans?

- sporozoite (transmission) - gametocyte (sexual reproduction) - other stages

What do apicomplexans contain and what is it?

they contain apicoplasts which are degenerated chloroplasts that lack pigments and phototrophic capacity

What do apicomplexans cause?

- malaria from Plasmodium - toxoplasmosis from Toxoplasma - coccidiosis from Eimeria

What is the characteristic of Stramenopiles?

they have flagella with many short hairlike extensions

What are the three subcategories of of Stramenopiles?

- Oomucetes - Diatoms - Golden algae

Oomycetes are _____. They are also called _____.

chemoheterotrophs; water molds

Golden algae are _____. They are also called _____.

phototrophs; chrysophytes

What are the characteristics of Oomycetes?

- they have coenocytic hyphae (multinucleate) | - their cell wall is made of cellulose not chitin

What gives the golden brown color of golden algae?

the chloroplasts pigments are dominated by the carotenoid FUCOXANTHIN

Diatoms are ____. They are the most important _____.

phototrophic; primary producers

What are the cell walls of diatoms made of?

silica [frustules (organism)]

What distinguishes Cercozoans and Radiolarians from other protists?

their threadlike pseudopodia

Name of ornate shell-like structures of cercozoans and radiolarians?

tests

What are tests made of in cercozoans?

organic material

What are tests made of in radiolarians?

silica

Cercozoans and Radiolarians are _____.

unicellular

Amoebozoas use _____ to move and feed. They move by _____ movement.

pseudopodia; amoeboid

What are the three major groups of amoebozoas?

- gymnamoebas - slime molds - entamoebas

Gymnamoebas and entamoebas are _____. An example is ______.

unicellular; Entamoeba histolytica

Why were Slime molds previously grouped with fungi?

because they have similar life cycles: produce fruiting bodies with spore for dispersal

What are the two types of slime molds?

- cellular slime mold | - plasmodial slime molds

What is the vegetative form of plasmodial slime molds?

masses of protoplasm (cytoplasm, nucleus, organelles) of indefinite size and shape (plasmodium), that contain multiple nuclei

What forms from a plasmodium?

a sporangium containing multiple haploid spores (dormant, resistant, for dispersal)

What happens to the spores of plasmodial slime molds?

they germinate yielding a swarmer cell (flagellated or amoeboid).

The fusion of 2 ______ regenerates the diploid plasmodium.

swarmer cells

What is the vegetative form of cellular slime molds?

it is composed of single amoebae (haploid)

What forms a pseudoplasmodium in cellular slime molds?

aggregate of separate amoeboid cells

Fungi can be multicellular: ____ or unicellular: ____

molds; Yeats

What are the two types of hyphae in multicellular fungi?

- coenocytic: cytoplasm and nuclei are not subdivided into cells - septet: nuclei are separated by cross wall (1 nucleus per cell)

Hyphae that extend above the surface can produce asexual spores celled ____.

conidia

Fungal cell walls are made of ____.

chitin

What are the 3 types of haploid sexual spores produced by fungi?

- ascospores - basidiospores - zygospores

______ help plant roots obtain phosphorus.

Mycorrhizae

What do we call the close relationship between some species of fungi with plant roots?

a symbiotic association

What is the association between fungi and algae/cyanobacterium called?

Lichen

What are the two types of mycorrhizae?

Ectomycorrhizae and endomycorrhizae

Which mycorrhizae forms a sheath around the plant root but doesn't penetrate it?

Ectomycorrhizae

Which mycorrhizae has a fungal hyphae embedded in the plant root?

Endomycorrhizae

What are the specialized hyphae formed by fungal plant pathogens called that penetrate the plant cells and consume the cytoplasm?

haustoria

______ in humans range in severity from "athlete's foot" to histoplasmosis. ________ is a major risk factor

Mycoses; immunosuppression

Most fungi reproduce by _____.

asexual means

What are the three forms of asexual reproduction?

- growth and spread of hyphal filaments - asexual production of spores - simple cell division: budding yeast

Some fungi produce ___ as a result of sexual reproduction.

spores

The sexual spores produced by fungi are resistant to ____, ____, ____, and ____.

drying, heating, freezing and chemicals

What is yeast and give an example.

unicellular fungi. ex: Sacchromyces cerevisiae

Cell division of yeast is through ____.

budding

the sexual reproduction of yeast involves mating between __ and __.

a and alpha