General Biology 2 Exam 1 Chapter 29

heterotrophs

-- absorb organic molecules or ingest larger food particles

mixotrophs

-- combine photosynthesis and heterotrophic nutrition

photoautotrophs

-- contain chloroplasts

heteromorphic

-- generations are structurally different

isomorphic

-- generations look similar

plastids

-- may have evolved by endosymbiosis of a photosynthetic cyanobacterium

mitochondria

-- may have evolved by endosymbiosis of an aerobic prokaryote

protist

-- the informal name of the kingdom of mostly unicellular eukaryotes

excavata chromalveolata rhizaria archaeplastida unikonta

5 super groups of eukaryotes (including protists): -- -- -- -- --

archaeplastida

Supergroup includes red algae, green algae, and land plants

parasitic protists

are parasitic

symbiotic protists

benefit their hosts

slime molds

part of amoebozoans once thought to be fungi

tests

porous, generally multichambered shells

endosymbiosis

protist diversity has its origins in --

eukaryotes unicellular

protists are --, and most are --

structural functional

protists exhibit more -- and -- diversity than any other group of eukaryotes

thallus

the algal body that is plantlike but lacks true roots, stems, and leaves

alternation of generations

the most complex life cycles include an -- -- --, the alternation of multicellular haploid and diploid forms

rhizaria

•Supergroup •DNA evidence supports - as a monophyletic clade •amoebas move and feed by pseudopodia; some but not all belong to the clade - •include forams and radiolarians

Chromalveolata

•Supergroup •data suggest that its monophyletic and originated by a secondary endosymbiosis event •proposed emdosymbiont is red alga •most are photosynthetic •includes the alveolates and the stremenopiles

unikonta

•Supergroup •includes animals, fungi, and some protists •two clades: the amoebozoans and the opisthokonts •unclear whether - separated from other eukaryotes relatively early or late

excavata

•Supergroup •includes protists with modified mitochondria and protists with unique flagella •characterized by its cytoskeleton •some members have a feeding groove (excavated) •includes diplomonads, parabasalids, and euglenozoans

plasmodial slime molds

•are brightly pigmented, usually yellow or orange •at one point in the life cycle they form a mass called plasmodium •undivided by membranes and contains many diploid nuclei •extends pseudopodia through decomposing material, engulfing food by phagocytosis

photosynthetic protists

•are important producers that obtain energy from the sun •main producers in aquatic environments

cellular slime molds

•form multicellular aggregates in which cells are separated by their membranes •cells feed individually, but can aggregate to form a fruiting body •dictyostelium discoideum is an experimental model for studying the evolution of multicellularity

euglenids

•have one or two flagella that emerge from a pocket at one end of the cell •can be both autotrophic and heterotrophic

protists

•often play the role of symbiont or producer •found in diverse aquatic environments

gymnamoebas

•part of amoebozoans •common unicellular amoebozoans in soil as well as freshwater and marine environments •most are heterotrophic and actively seek and consume bacteria and other protists

entamoebas

•part of amoebozoans •parasites of vertebrates and some invertebrates •entamoeba histolytica causes amebic dysentery in humans

green algae

•part of archaeplastida named for their chloroplasts plants are descended from - •two main groups are chlorophytes and charophyceans

red algae

•part of archaeplastida •reddish in color due to an accessory pigment called phycoerythrin, which masks the green of chlorophyll •color varies from greenish-red in shallow water to dark red or almost black in deep water •usually multicellular; the largest are seaweed •most abundant large algae in coastal waters of the tropics

kinetoplastids

•part of euglenozoans •have single mitochondrian with an organized mass of DNA called kinetoplast •include free-living consumers of prokaryotes in freshwater, marine, and moist terrestrial ecosystems •includes Trypanosoma, which causes sleeping sickness in humans causes Chagas' disease

diplomonads

•part of excavata •have mitochondria called mitosomes •derive energy anaerobically, for example, by glycolysis •have 2 equal-sized nuclei and multiple flagella •are often parasites, for example, Giardia intestinalis

euglenozoans

•part of excavata •includes predatory heterotrophs, photosynthetic autotrophs, and pathogenic parasites •spiral or crystalline rod of unknown function inside their flagella •includes the kinetoplastids and euglenids

parabasalids

•part of excavata •have reduced mitochondria called hydrogenosomes that generate energy anaerobically •include trichomonas vaginalis, the pathogen that causes yeast infections in human females

radiolarians

•part of rhizaria •marine protists called - have tests fused into one delicate piece, usually made of silica •use their pseudopodia to engulf microorganisms through phagocytosis •the pseudopodia radiate from the central body

golden algae

•part of stramenopiles •are named for their color, which results from their yellow and brown carotenoids •all cells are typically biflagellated, with flagella near one end all are photosynthetic, and some are also heterotrophic •most are unicellular, but some are colonial

oomycetes

•part of stramenopiles •includes water molds, white rusts, and downy mildews •once considered fungi based on morphological studies •most are decomposers or parasites •they have filaments (hyphae) that facilitate nutrient uptake •ecological impact can be great, as in phytophthora infestans causing potato blight

brown algae

•part of stramenopiles •largest and most complex algae are multicellular and most are marine •include many species commonly called seaweeds •have the most complex multicellular anatomy of all algae

dinoflagellates

•part of the alveolates •a diverse group of aquatic mixotrophs and heterotrophs •abundant components of both marine and freshwater phytoplankton •each has a characteristic shape that in many species is reinforced by internal plates of cellulose •two flagella •blooms are cause of toxic "red tides"

ciliates

•part of the alveolates •a large varied group of protists, are named for their use of -- to move and feed •have a large macronuclei, and a small micronuclei •the micronuclei function during conjugation

apicomplexans

•part of the alveolates •parasites of animals, and some cause serious human disease •one end, the apex, contains a complex of organelles specialized for penetrating a host •most have sexual and asexual stages that require two or more different host species for completion •the -- Plasmodium is the parasite that causes malaria

alveolates

•part of the chromalveolates •have membrane bound sacs (alveoli) just under the plasma membrane •includes dinoflagellates, apicomplexans, and ciliates

stramenopiles

•part of the chromalveolates •includes several groups of heterotrophs as well as certain groups of algae •diatoms, golden & brown algae, oomycetes •most have "hairy" flagellum paired with a "smooth" flagelum

diatoms

•part of the stramenopiles •unicellular algae with a unique two- part, glass-like wall of hydrated silica •usually reproduce asexually, and occasionally sexually •a major component of phytoplankton and are highly diverse •fossilized - walls compose much of the sediments known as diatomaceous earth

amoebozons

•part of unikonta •are amoeba that have lobe- or tube-shaped, rather than threadlike, pseudopodia •include gymnamoebas, entamoebas, and slime molds

opisthokonts

•part of unikonta •include animals, fungi, and several groups of protists

forams

•part or rhizaria •are named for porous, generally multichambered shells, called tests •pseudopodia extend through the pores in the test •foram tests in marine sediments form an extensive fossil record