Chapter 27 Flashcards
Eukaryotes: Two Domains United
prevents freshwater single-celled eukaryotes from lysing when water enters the cell by osmosis
contractile vacuoles
digest prey or other organic material engulfed by the cells
food vacuoles
a layer of supportive protein fibers located inside the cell, just under the plasma membrane, provides strength and flexibility instead of a cell wall
pellicle
one or more lobes of cytoplasm that when extended, help single-celled eukaryotes move by amoeboid motion(“false feet”)
pseudopodia
photosynthetic small eukaryotes carried around passively by water currents
phytoplankton
small eukaryotes carried around passively by water currents that are not photosynthetic
zooplankton
a level of classification below domain but above kingdom
supergroup
original event that led to the evolution of the first chloroplasts
primary endosymbiosis
event in which photosynthesis evolved in other branches of eukaryotes by endosymbiosis not of cyanobacteria, but of green or red algae
secondary endosymbiosis
chemotrophs; feed by phagocytosis or secreting enzymes that break down macromolecules; cell membranes not reinforced by cell walls or pellicles or cell walls to protect all cells or specific cell types; single-celled, colonial or multicellular; free-living or parasitic; marine, freshwater, terrestrial
amorphea
single-celled eukaryote; moves by means of temporary cellular projections called pseudopods; evolved independently in several groups of eukaryotes
amoeba
a type of amoeba; includes cellular and plasmodial slime molds; all members use pseudopods for locomotion and feeding
amoebozoa
chemotrophic eukaryotes that exist as single amoeboid cells during parts of their life cycle; live on moist, rotting plant material
slime molds
fungus-like, stalked structure that forms spores by either asexual or sexual reproduction
fruiting body
slime molds that exist primarily as individual cells, either separately or as a coordinated mass
cellular slime molds
slime molds that exist primarily as a large mass of cytoplasm
plasmodial slime molds
a large mass of cytoplasm in which many individual nuclei are surrounded by a single plasma membrane
plasmodium
include animals, fungi, and related organisms; have a single flagellum at the posterior pole of their cells at some stage of their life cycle
opisthokonta
chemotrophic, predominantly spherical amoebas with radiating, fine pseudopods not supported by microtubules
nucleariidae
a collar of closely packed microvilli that surrounds a single flagellum
choanoflagellata
consist of Rhodophyta(red algae), Chlorophyta(green algae), and land plants(compromise kingdom Plantae)
Archaeplastida
consist of about 4,000 known species, most of which small marine seaweeds
Rhodophyta (red algae)
extract used as moisture-preserving, inert agent in cosmetics and baked goods, setting agent for jellies & desserts, solidifying agent for culture medium in lab
agar
extract from red algae Eucheuma; used to thicken and stabilize paints, dairy products such as pudding and ice cream
Carrageenan
phototrophs that use the same photosynthetic pigments as plants
Chlorophyta (green algae)
green algae more closely related to plants than to other green algae
charophytes
a fuel produced from a living organism that can be acquired by extracting their lipids
biofuel
group that include algae and fungus-like chemotrophs; have two different flagella: one with hollow tripartite projections that give flagellum a “hairy” appearance and a second one that is plain
Stramenopila
funguslike stramenopiles that lack chloroplasts and live as chemotrophs (water molds, white rusts, and downy mildews)
Oomycota
microscopic, nonmotile filaments that Oomycota grows on
hyphae
a network of hyphae
mycelium
single-celled organisms that are covered by a glassy silica shell
Bacillariophyta (diatoms)
mostly are colonial forms in which each cell of the colony bears a pair of flagella; glassy shells in forms of plates or scales; nearly all phototrophs; color is due to brownish carotenoid pigment fucoxanthin masking green color of chlorophylls
Chrysophyta (golden algae)
photosynthetic phototrophs that range from microscopic forms to giant kelps; color from fucoxanthin
Phaeophyta (brown algae)
large structures recognized as kelps and other brown seaweeds that give rise to haploid spores by meiosis
sporophytes
the extracted alginic acid in brown algal cell walls; an essentially tasteless and nontoxic substances used to thicken diverse products
algin
have small, flattened, membrane-bound vesicles in a layer just below the plasma membrane
alveolates
two motile, primarily free-living groups included in the alveolata
Ciliophora & Dinoflagellata
a nonmotile, parasitic group
Apicomplexa
include nearly 10,000 known species of primarily single-celled but highly complex chemotrophic organisms that swim by means of cilia; contained in essentially any sample of pond water or bottom mud
Ciliophora (ciliates)
a diploid nucleus that contains a complete complement of genes
micronucleus
develop from a micronucleus, but lose all genes except those required for basic “housekeeping” functions of the cell; remaining DNA sequences are duplicated many times, greatly increasing cell’s capacity to transcribe rRNAs needed to make ribosomes & mRNAs coding for proteins that cell needs in large quantities
macronucleus
form a cytoplasmic bridge between two cells, recombining their genetic information by exchanging micronuclei
conjugate
surface organelles that discharge dartlike protein threads when ciliates are under attack or otherwise stressed
trichocysts
consists of over 4,000 known species, most of which are single-celled organisms in marine phytoplankton; live as chemotrophs or phototrophs; major primary producer of ocean ecosystems
Dinoflagellata
being able to glow or release a flash or light, particularly when disturbed
bioluminescent
results of dinoflagellate populations growing to such numbers they color the seas red, orange, or brown
red tides
non-motile parasites of animals that absorb nutrients through their plasma membranes rather than engulfing food particles; lack food vacuoles
Apicomplexa
single-celled amoebas with narrow, stiff pseudopodia
Rhizaria
group of Rhizdarian that are distinguised by axopods: slender, raylike strands of cytoplasm supported internally by long bundles of microtubules
Radiolaria (radiolarians)
group of Rhizaria that have shells consisting of organic matter reinforced by calcium carbonate
Foraminifera (forams)
green, photosynthetic amoebas that engulf food; contain chlorophyll a and b; many filamentous pseudopodia extend from cell surface
Chlorarachniophyta (chlorarachniophytes)
diverse group of single-celled organisms; most chemotrophs but some capable of photosynthesis; occupy marine and freshwater habitats; most free-living, some live as parasites or symbionts in guts of animal; a scooped out (excavated) feeding apparatus on ventral surface of cell
Excavata
two major subgroups of the Excavata
Metamonada & Euglenozoa
a sort of fin formed by a flagellum buried in a fold of the cytoplasm; allows parabasalids to move through thick and viscous fluids
undulating membrane
include both phototrophs and chemotrophs; include about 1,800 species; almost all single-celled, highly motile cells that swim by means of flagella; functional mitochondria characterized by cristae(inner mitochondria membranes); most photosynthetic, some facultative chemotrophs
Euglenozoans
a group of Euglenozoans; free-living eukaryotes with anterior flagella that pull cells through the water; inhabit freshwater ponds, streams, lakes; most phototrophs
Euglenids
a group of Euglenozoans; chemotrophic cells that live as animal parasites; single mitochondrion containing a large DNA-protein deposit called kinetoplast
Kinetoplastids
