Chapter 28 Part C: Rhizarians And Unikonta Flashcards
What does the “R” in SAR stand for?
Rhizarians
Many species of rhizarians are ________.
Amoebas
__________ are protists that move and feed using _____________, extensions of the cell surface.
Amoebas; pseudopodia
Why do Rhizarian amoebas differ from amoebas in other clades?
They have threadlike pseudopodia
What are the 3 clades of Rhizarians
Radiolarians, forams, and cercozoans
Which subgroup of the Rhizarians have delicate, symmetrical internal typically made of ________.
Radiolarians; silica
What radiates from the central body in Radiolarians?
Pseudopodia reinforced by microtubules
In Radiolarians, prey are engulfed by cytoplasm in the _____________ and carried into the cell by ____________ ____________.
Pseudopodia; cytoplasmic streaming
Most radiolarians are _________ organisms
Marine
What is another name for the subgroup Forams?
Foraminiferans
Forams are named for their porous _________ __________ shells, called _______.
Calcium carbonate; tests
What three things are psuedopodia used in?
Swimming, test formation, and feeding
What do forams host within their tests?
Mutualistic photosynthetic algae
Where do Forams live?
Ocean and fresh water
Forams’ _______ make up part of the ________ sediments
Fossils; marine
What are used for correlating the age of sedimentary rocks in different parts of the world
Fossilized tests
The ___________ ________ of the fossilized tests is used to estimate the change in ocean _________ over time.
Magnesium content; temperature
What is the last subgroup of Rhizarians?
Cercozoans
Are amoeboid and flagellated protists
Cercozoans
A Rhizarians subgroup that feeds using threadlike pseudopodia.
Cercozoans
Where are the 3 common places to find Cercozoans?
Marine, fresh water, and soil ecosystems
Most cercozoans are heterotrophic ___________ or __________.
Parasites; predators
This is a small group of ____________ that is a part of the subgroup Cercozoans
Mixotrophs; Chlorarachniophytes
An example of a Cercozoans; it is known to be __________.
Paulinella chromatophora; autotrophic
Paulinella chromatophora has a unique photosynthetic structure called
Chromatophore
What are derived from endosymbiosis with a Cyanobacteria different from the one that gave rise to ________.
Chromatophores; plastids
What are the closest relatives of plants?
Red and green algae
__________ arose when a heterotrophic protist acquired a Cyanobacteria ___________.
Plastids; endosymbiont
_________ are descended from the ______ algae.
Plants; green
The supergroup that includes red algae, green algae, and plants
Archaeplastida
What gives red algae its color?
Phycoerythrin
What is phycoerythrin?
An accessory pigment that masks the green of chlorophyll
What color of red algae shows in shallow water?
Greenish-red
What color of red algae shows in deep water?
Dark red or almost black
Most red algae are _________.
Multicellular
Example of red algae
Largest are seaweeds
Reproduction is ________ in ____ algae
Sexual; red
The life cycles of red algae often include _____________ ___ ________________.
Alternation of generations
Where are red algae common?
Coastal waters of tropical oceans
Some species of red algae are consumed by _______, such as _________ (“nori”) that is used to wrap sushi
Humans; Porphyra
________ algae are named for their green ____________
Green; chloroplasts
Have chloroplasts that are structurally and chemically similar to those found in plants
Green algae
Green algae form a ____________ group
Paraphyletic
What does the paraphyletic group include?
Charophytes and chlorophytes
Include algae most closely related to plants
Charophytes
T/F: Chlorophytes only live in fresh water
F: They most live in fresh water, there are many marine and some terrestrial species
Green algae have various __________ species that are ______-_______ while others live ___________ with other eukaryotes
Unicellular; free-living; symbiotically
What kind of environments do some green algae live in?
Exposed to intense visible and ultraviolet radiation
The first mechanism that caused larger size and greater complexity to evolve in green algae?
- Formation of colonies from individuals cells
What is an example of the 1st mechanism
Pediastrum
The second mechanism that caused larger size and greater complexity to evolve in green algae?
Formation of true multicellular bodies by cell division and differentiation
Wha are examples of the second mechanism
Volvox and Ulva
The third mechanism that caused larger size and greater complexity to evolve in green algae?
Repeated division of nuclei with no cytoplasmic division
What is an example of the third mechanism
Caulerpa
Have complex life cycles with both sexual and asexual reproductive stage
Most chlorophytes
T/F: Nearly all species of green algae have flagellated gametes with flat-shaped chloroplasts.
F: biflagellated gametes with cup-shaped chloroplasts
Alternation of generations has evolved in some _____________, including ______
Chlorophytes; Ulva
This supergroup includes protists that are closely related to fungi and animals
Unikonts
What are the 2 major clades of unikonts?
Amoebozoans and opisthokonts
What are a part of the amoebozoans?
Tubulinids, slime molds, and entamoebas
What are a part of the opisthokonts?
Animals, fungi, and related protists
Controversial hypothesis: Unikonts were the _________ to diverge from other __________ groups
First; eukaryote
Amoebas that have lobe- or tube- shaped, rather than threadlike, ______________
Amoebozoans; pseudopodia
Where are Tubulinids common?
Unicellular protists in soil as well as freshwater and marine environments
Most Tubulinids are active _______ of bacteria and other protists; other feed on __________
Predators; detritus
Another name for slime molds
Mycetozoans
What were slime molds once thought to be? Why?
Fungi; spore-producing fruiting bodies
Slime molds thought to be fungi is a result of
Convergent evolution
What are the two lineages of slime molds?
Plasmodia slime molds and cellular slime molds
What is the structure within slime molds?
Plasmodial slime molds
Brightly colored, often yellow or orange
Plasmodial slime molds
Large feeding mass formed by Plasmodial slime molds
Plasmodium
Single “supercell” that contains many diploid nuclei undivided by plasma membranes
Plasmodium
Forms a fruiting body for sexual reproduction in unfavorable environmental conditions
Plasmodium
Form multicellular aggregate in which cells are separated by plasma membranes
Cellular slime molds
Feeding stage consists of solitary cells
Cellular slime molds
__________ cells unite to form a ____-like aggregate for ___________ when habitat conditions are ______
Solitary; slug; migration; poor
What ultimately forms a fruiting body in cellular slime molds?
Aggregated cells
Model organism for the studying of evolution of multicellularity
Dictyostelium discoideum
_______ in the stalk of the fruiting body ____ without reproducing
Cells; die
Cells at the _____ survive to _________
Top; reproduce
Some cells have a “_______” mutation, giving them the reproductive __________ of not forming the _____
Cheat; advantage; stalk
What type of cells lack a specific surface protein recognized by noncheaters
Cheating cells
What cells avoid exploitation by preferentially aggregating with other noncheaters?
Non-cheaters
Parasites of all classes of vertebrates and some invertebrates
Entamoeba
Humans host at least _____ species, but only _____________ is pathogenic
6; E. Histolytica
Causes amoebic dysentery, the third-leading cause of death due to eukaryotic parasites
E. Histolytica
Are a diverse group including animals, fungi, and several groups of protists
Opisthokonts
What play key roles in ecological communities?
Protists
What environments are protist found in?
Diverse aquatic and moist terrestrial environments
What are the two roles that protists play in their habitats?
Symbiont and producer
What kind of protist benefit their host?
Symbiotic protist
Parasites
Protist symbionts
Symbiotic protist that causes malaria in humans?
Plasmodium
Symbiotic protist dinoflagellate that attached and feeds on the skin of fish
Pfiesteria shumwayae
Symbiotic protist that causes sudden oak death
Phytophthora Ramorum
Organisms that use energy from light (or inorganic compounds) to convert to organic compounds
Producers
In aquatic communities, who are the main producers?
Photosynthetic protists and prokaryotes
Directly or indirectly depend on producers for food
Consumers
Limited by nutrients; populations explode when nutrients are added
Photosynthetic protists
Have declined with increasing sea surface temperature
Growth and biomass of photosynthetic protists and prokaryotes
Acts as a barrier to upwelling
Warm surface water
3 things affected if sea surface temperature continues to warm
Marine ecosystems, fishery yields, and global carbon cycle