Biology Chapter 26 - Protists

Define sporozoite.

The infective spore-like state in apicocomplexans.

True or False? Water molds have coenocytic mycelium.

True

These include fungi and animals, and and share a single posterior flagellum in flagellate cells. What are they?

Unikonts

How do water molds reproduce asexually vs sexually?

Water molds reproduce asexually by forming biflagellate zoospores and sexually by forming oospores.

__________ are unicellular and flagellate, and some are photosynthetic.

Euglenoids

Protists have various means of locomotion including:

pseudopodia, flagella, cilia, and a few are nonmotile

Some dinoflagellates produce toxic blooms known as what?

red tides

Most __________ have motile cells with two flagella m one of which has tiny hairlike projections off the shaft.

stramenopiles

Which apicomplexan causes malaria?

the apicomplexan Plasmodium

What is ultrastructure?

the dine details of cell structure revealed by electron microscopy, and by comparative molecular data.

What are amoeboid cells that often have hard outer shells called tests, through which cytoplasmic projections extend?

Rhizarians

________ are multicellular stramenopiles that are ecologically important in cooler ocean waters.

Brown algae

What kind of algae possesses leaflike blades, stemlike stiles, anchoring holdfasts, and gas filled bladders for buoyancy?

Brown algae (kelps)

How does reproduction occur in plasmodial slime molds?

By haploid spores produced within sporangia.

___________ are anaerobic, flagellated excavates that other live in animals .

Parabasilids

Where do PARASITIC protists live?

Parasitic protists live in the body fluids or cells of their hosts.

What probably originated as a result of secondary endosymbiosis in which an ancestral cell engulfed a red alga?

Chromalveolates

________ are alveolates that move by hairlike cilia, have micronuclei (for sexual reproduction) and micronuclei (for controlling cell metabolism and growth), and undergo a sexual process called conjugation,

Ciliates

Which of the following is not true of the protists? (a) they are unicellular, colonial coenocytic, or simple multicellular organisms. (b) their cilia and flagella have a 9 + 2 arrangement of microtubules (c) they are prokaryotic, as bacteria and archaea are (d) some are free-living, and some are endosymbionts (e) most are aquatic and live in the ocean or in freshwater ponds

(c) they are prokaryotic, as bacteria and archaea are

What type of rhizarians are mostly marine plankton that obtain food by means of axopods?

Actinopods

These feed as individual amoeboid cells and reproduce by aggregating into an aggregate (slung) and then forming asexual spores. What are they?

Cellular slime molds

___________ are unikonts that are probably the closest living non-animal relative of animals.

Choanoflagellates

_________ are mostly unicellular, with shells containing silica and some are part of floating plankton and others love on rocks and sediments where they move by gliding.

Diatoms

__________ are excavates, organisms with a deep, or excavated, oral groove and have one or two nuclei, no functional mitochondria, no Golgie complex, and up to eight flagella.

Diplomonads

True or False? Protists ONLY reproduce asexually.

False. Many protists reproduce sexually or asexually; others reproduce only asexually.

True or False? Protists are not free-living, nor symbiotic.

False. Protists are free-living or symbiotic, with symbiotic relationships ranging from mutualism to parasitism.

True or False? Red algae, green algae, and land plants, collectively called archaeplastids, are considered a paraphyletic group.

False. These archaeplastids are considered a monophyletic group based on the presence of chloroplasts bounded by outer and inner membranes.

What type of rhizarians secrete many-chambered tests with pores through which cytoplasmic projections extend to move and obtain food?

Forams

_______ are mostly unicellular, biflagellate freshwater and marine stramenopiles that are of ecological importance as a component of the ocean's extremely minute nanoplankton.

Golden algae

What exhibit a wide diversity in size, structural complexity, and reproduction, and botanists hypothesize that these gave rise to to land plants?

Green algae

What have biologists compared in different protist taxa?

Many biologists have compared nuclear genes in protists taxa, many of which code for proteins.

Where do most protists live?

Most protists live in the ocean or in fresh water ponds, lakes, and streams.

What is the feeding stage of plasmodial slime molds?

Multinucleate plasmodium

Trichonymphs and trichomonads are examples of what?

Parabasilids

What are ecologically important in warm tropical ocean waters? (HINT: They are multicellular seaweeds)

Red algae

What does molecular evidence indicate about Rhizarians?

Rhizarians are monophyletic.

Which hypothesis does the following describe? Mitochondria and chloroplasts arose from symbiotic relationships between larger cells and the smaller bacteria that were incorporated and lived within them.

The hypothesis of serial endosymbiosis

True or False? Protists are able to obtain nutrients both autographically and heterotrophically.

True.

True or False? Some DNA sequence data suggest chromalveolates are NOT monophyletic.

True.

What are the three alveolates?

dinoflagellates, apicomplexans, and ciliates

Which three types of organisms are controversially included in the excavate superfamily?

diplomonads, parabaslids, and euglenoids

A collar of __________ surrounds the choanoflagelletes' single flagellum at the base.

microvilli

By what are relationships among protists largely determined?

ultrastructure

What are the types of stramenopiles?

water molds, diatoms, golden algae, and brown algae

_________ have similar ribosomal DNA sequences and alveoli, flattened vesicles located just inside the plasma membrane.

Alveolates

What are flattened vesicles under the plasma membrane, that often contain cellulose plates impregnated with silicates called?

Alveoli

These move and obtain food by phagocytosis, using cytoplasmic extensions called pseudopodia. What are they?

Amoebas

What structure attaches an apicomplexan to its host cell?

An apical complex of microtubules

__________ are parasites that produce sporozoites and are nonmotile.

Apicomplexans

Chloroplasts of red algae, green algae, and plants probably arose in a single primary endosymbiotic event in which a __________ was incorporated into a cell.

Cyanobacteria

__________ are mostly unicellular, biflagellate, photosynthetic alveolates of great ecological importance as producers in marine ecosystems.

Dinoflagellates

Which kind of organisms make up a diverse group of unicellular protists with flagella, an excavated oral groove, and atypical, greatly modified mitochondria?

Excavates

What led to chloroplasts in euglenoids, dinoflagellates, diatoms, golden algae, and brown algae and to the nonfunctional chloroplasts in apicomplexans?

Multiple secondary enosymbioses

What are slender cytoplasmic projections that extend through pores in the shells of actinopods?

axopods