Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
75 Cards in this Set
- Front
- Back
Protists are...
Eukaryotic cells have... It is important to bear in mind that... |
Protists are eukaryotes
Eukaryotic cells have organelles and are more complex than prokaryotic cells It is important to bear in mind that 1. The organisms in most eukaryotic lineages are protists 2. Most protists are unicellular |
|
Protists exhibit more structural and functional diversity than...
Though most protists are unicellular, there are... Single-celled protists can be very complex, as all biological functions are carried out by... |
Protists exhibit more structural and functional diversity than any other group of eukaryotes
Though most protists are unicellular, there are some colonial and multicellular species Single-celled protists can be very complex, as all biological functions are carried out by organelles in each individual cell |
|
Protists, the most nutritionally diverse of all eukaryotes, include...
|
Protists, the most nutritionally diverse of all eukaryotes, include:
1. Photoautotrophs, which contain chloroplasts 2. Heterotrophs, which absorb organic molecules or ingest larger food particles 3. Mixotrophs, which combine photosynthesis and heterotrophic nutrition |
|
Some protists reproduce asexually, while...
|
Some protists reproduce asexually, while others reproduce sexually, or by the sexual processes of meiosis and fertilization
|
|
Four Supergroups of Eukaryotes
It is no longer thought that amitochondriates (lacking mitochondria) are the oldest lineage of eukaryotes Many protists have been shown to have... One hypothesis divides all eukaryotes (including protists) into... |
Four Supergroups of Eukaryotes
It is no longer thought that amitochondriates (lacking mitochondria) are the oldest lineage of eukaryotes Many protists have been shown to have mitochondria and have been reclassified Our understanding of the relationships among protist groups continues to change rapidly One hypothesis divides all eukaryotes (including protists) into four supergroups |
|
There is now considerable evidence that much protist diversity has its origins...
Endosymbiosis is a relationship between... |
There is now considerable evidence that much protist diversity has its origins in endosymbiosis
Endosymbiosis is a relationship between two species in which one organism lives inside the cell or cells of the other organism (the host) |
|
Mitochondria and plastids are derived from prokaryotes that...
Mitochondria evolved once by... Plastids evolved later by... The ancestral host cell may have been... |
Mitochondria and plastids are derived from prokaryotes that were engulfed by the ancestors of early eukaryotic cells
Mitochondria evolved once by endosymbiosis of an alpha proteobacterium Plastids evolved later by endosymbiosis of a photosynthetic cyanobacterium The ancestral host cell may have been an archaean or a “protoeukaryote,” from a lineage related to, but diverged from archaeal ancestors |
|
Mitochondria arose first through descent from a bacterium that was...
The plastid lineage evolved later from... The plastid-bearing lineage of protists evolved into... |
Mitochondria arose first through descent from a bacterium that was engulfed by a cell from an archaeal lineage
The plastid lineage evolved later from a photosynthetic cyanobacterium that was engulfed by a heterotrophic eukaryote The plastid-bearing lineage of protists evolved into photosynthetic protists, red and green algae |
|
Illustrate the arrival of plastids, beginning with the most recent common ancestor.
|
|
|
Like cyanobacteria, plastids of red algae and green algae have... Transport proteins in the membranes of red and green algae are homologous to... |
Like cyanobacteria, plastids of red algae and green algae have two membranes
Transport proteins in the membranes of red and green algae are homologous to those found in cyanobacteria |
|
On several occasions during eukaryotic evolution, red and green algae underwent ...
For example, chlorarachniophytes likely evolved when... |
On several occasions during eukaryotic evolution, red and green algae underwent secondary endosymbiosis, in which they were ingested by a heterotrophic eukaryote
For example, chlorarachniophytes likely evolved when a heterotrophic eukaryote engulfed a green alga The engulfed cell contains a vestigial nucleus called a nucleomorph |
|
Illustrate the basic morphology of the Chlorarachniophyte.
|
|
|
Concept 28.2: Excavates include protists with modified...
The clade Excavata is characterized by... Some members have an “excavated”... This group includes the... |
Concept 28.2: Excavates include protists with modified mitochondria and protists with unique flagella The clade Excavata is characterized by its cytoskeleton Some members have an “excavated” feeding groove This group includes the diplomonads, parabasalids, and euglenozoans |
|
Diplomonads and Parabasalids
These two groups lack... and most live in... Diplomonads -Have reduced mitochondria called... -Derive energy from ... -Have two equal-sized ... and multiple ... -Are often... |
Diplomonads and Parabasalids -These two groups lack plastids, have modified mitochondria, and most live in anaerobic environments Diplomonads -Have reduced mitochondria called mitosomes -Derive energy from anaerobic biochemical pathways -Have two equal-sized nuclei and multiple flagella Are often parasites, for example, Giardia intestinalis |
|
Parabasalids
Have reduced mitochondria called ... that generate some ... Include ... |
Parabasalids Have reduced mitochondria called hydrogenosomes that generate some energy anaerobically Include Trichomonas vaginalis, the pathogen that causes yeast infections in human females |
|
Euglenozoans
Euglenozoa is a diverse clade that includes predatory... The main feature distinguishing them as a clade is... This clade includes... |
Euglenozoans Euglenozoa is a diverse clade that includes predatory heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites The main feature distinguishing them as a clade is a spiral or crystalline rod inside their flagella This clade includes the kinetoplastids and euglenids |
|
Kinetoplastids
Kinetoplastids have a single... Free-living species are consumers of... |
Kinetoplastids Kinetoplastids have a single mitochondrion with an organized mass of DNA called a kinetoplast Free-living species are consumers of prokaryotes in freshwater, marine, and moist terrestrial ecosystems Some species are parasitic Kinetoplastids in the genus Trypanosoma cause sleeping sickness in humans Another pathogenic trypanosome causes Chagas’ disease |
|
Kinetoplastids (cont'd) Trypanosomes evade immune responses by...A cell produces millions of... These frequent changes prevent... |
Trypanosomes evade immune responses by switching surface proteins A cell produces millions of copies of a single protein The new generation produces millions of copies of a different protein These frequent changes prevent the host from developing immunity |
|
Euglenids
Euglenids have one or two... Some species can be... |
Euglenids Euglenids have one or two flagella that emerge from a pocket at one end of the cell Some species can be both autotrophic and heterotrophic |
|
Illustrate the morphology of Euglenids.
|
|
|
Describe the naming of the SAR clade.
This group is one of the most... |
Concept 28.3: The “SAR” clade is a highly diverse group of protists defined by DNA similarities The “SAR” clade is a diverse monophyletic supergroup named for the first letters of its three major clades stramenopiles, alveolates, and rhizarians This group is one of the most controversial of the four supergroups |
|
Illustrate the phylogeny of the SAR clade.
|
|
|
Stramenopiles
The stramenopiles clade includes some of the most important ... Most have a... Stramenopiles include... |
Stramenopiles The stramenopiles clade includes some of the most important photosynthetic organisms on Earth Most have a “hairy” flagellum paired with a “smooth” flagellum Stramenopiles include diatoms, golden algae, and brown algae |
|
Diatoms
Diatoms are unicellular... |
Diatoms Diatoms are unicellular algae with a unique two-part, glass-like wall of silicon dioxide |
|
Golden Algae
Golden algae are named for their... The cells of golden algae are typically ... All golden algae are... Most are... |
Golden Algae Golden algae are named for their color, which results from their yellow and brown carotenoids The cells of golden algae are typically biflagellated, with both flagella near one end All golden algae are photosynthetic, and some are mixotrophs Most are unicellular, but some are colonial |
|
Brown Algae
Brown algae are the largest and most... All are... Brown algae include many... |
Brown Algae Brown algae are the largest and most complex algae All are multicellular, and most are marine Brown algae include many species commonly called “seaweeds” |
|
Giant seaweeds called kelps...
Brown algal seaweeds have plantlike... Similarities between algae and plants are examples of... |
Giant seaweeds called kelps live in deep parts of the ocean Brown algal seaweeds have plantlike structures: the rootlike holdfast, which anchors the alga, and a stemlike stipe, which supports the leaflike blades Similarities between algae and plants are examples of analogous structures |
|
Illustrate the 3 main structural features of the Brown algal seaweeds.
|
|
|
Alternation of Generations
A variety of life cycles have evolved among... The most complex life cycles include an... Heteromorphic generations are structurally... |
Alternation of Generations A variety of life cycles have evolved among the multicellular algae The most complex life cycles include an alternation of generations, the alternation of multicellular haploid and diploid forms Heteromorphic generations are structurally different, while isomorphic generations look similar |
|
The diploid sporophyte produces haploid flagellated...
The zoospores develop into... Fertilization of gametes results in... |
The diploid sporophyte produces haploid flagellated spores called zoospores The zoospores develop into haploid male and female gametophytes, which produce gametes Fertilization of gametes results in a diploid zygote, which grows into a new sporophyte |
|
Illustrate the life cycle of zoospores, including meiosis and fertilization.
|
|
|
Alveolates
Members of the clade Alveolata have membrane-enclosed... The alveolates include... |
Alveolates Members of the clade Alveolata have membrane-enclosed sacs (alveoli) just under the plasma membrane The alveolates include: 1. Dinoflagellates 2. Apicomplexans 3. Ciliates |
|
Dinoflagellates
Dinoflagellates have two flagella... They are abundant... They are a diverse... Toxic "red tides" are caused by... |
Dinoflagellates Dinoflagellates have two flagella and each cell is reinforced by cellulose plates They are abundant components of both marine and freshwater phytoplankton They are a diverse group of aquatic phototrophs, mixotrophs, and heterotrophs Toxic “red tides” are caused by dinoflagellate blooms |
|
What causes Red tide in the Gulf of Carpentaria in Northern Australia.
|
|
|
Apicomplexans
Apicomplexans are parasites of animals, and some cause serious... They spread through... One end, the apex, contains... Most sexual and asexual... |
Apicomplexans Apicomplexans are parasites of animals, and some cause serious human diseases They spread through their host as infectious cells called sporozoites One end, the apex, contains a complex of organelles specialized for penetrating host cells and tissues Most have sexual and asexual stages that require two or more different host species for completion |
|
The apicomplexan Plasmodium is the parasite that causes...
Plasmodium requires both mosquitoes and... Approximately 900,000 people... Efforts are ongoing to... |
The apicomplexan Plasmodium is the parasite that causes malaria Plasmodium requires both mosquitoes and humans to complete its life cycle Approximately 900,000 people die each year from malaria Efforts are ongoing to develop vaccines that target this pathogen |
|
Illustrate the life cycle of Plasmodium.
|
|
|
Ciliates
Ciliates, a large varied group of protists, are named for their... They have large... Genetic variation results from... Conjugation is a... |
Ciliates Ciliates, a large varied group of protists, are named for their use of cilia to move and feed They have large macronuclei and small micronuclei Genetic variation results from conjugation, in which two individuals exchange haploid micronuclei Conjugation is a sexual process, and is separate from reproduction, which generally occurs by binary fission |
|
Rhizarians
Many species in the rhizarian clade are ... Amoebas are protists that... Rhizarian amoebas differ from amoebas in other clades by... Rhizarians include... |
Rhizarians Many species in the rhizarian clade are amoebas Amoebas are protists that move and feed by pseudopodia, extensions of the cell surface Rhizarian amoebas differ from amoebas in other clades by having threadlike pseudopodia Rhizarians include radiolarians, forams, and cercozoans |
|
Radiolarians
Marine protists called radiolarians have delicate... Radiolarians use their pseudopodia to... The pseudopodia of radiolarians... |
Radiolarians Marine protists called radiolarians have delicate, symmetrical internal skeletons that are usually made of silica Radiolarians use their pseudopodia to engulf microorganisms through phagocytosis The pseudopodia of radiolarians radiate from the central body |
|
Forams
Foraminiferans, or forams, are named for porous... Pseudopodia extend through... Many forams have... Foram tests in marine sediments form... |
Forams Foraminiferans, or forams, are named for porous, generally multichambered shells, called tests Pseudopodia extend through the pores in the test Many forams have endosymbiotic algae Foram tests in marine sediments form an extensive fossil record Researchers can use measures of the magnesium content in fossilized forams to estimate changes in ocean temperature over time |
|
Cercozoans
Cercozoans include most amoeboid and... They are common in... Most are... |
Cercozoans Cercozoans include most amoeboid and flagellated protists with threadlike pseudopodia They are common in marine, freshwater, and soil ecosystems Most are heterotrophs, including parasites and predators |
|
Paulinella chromatophora is an autotroph with...
This structure evolved from a different cyanobacterium than... |
Paulinella chromatophora is an autotroph with a unique photosynthetic structure called a chromoatophore This structure evolved from a different cyanobacterium than the plastids of other photosynthetic eukaryotes |
|
Concept 28.4: Red algae and green algae are the closest relatives of land plants
Plastids arose when a heterotrophic protist acquired a... The photosynthetic descendants of this ancient protist evolved into... Land plants are descended from... Archaeplastida is the supergroup that includes... |
Concept 28.4: Red algae and green algae are the closest relatives of land plants Plastids arose when a heterotrophic protist acquired a cyanobacterial endosymbiont The photosynthetic descendants of this ancient protist evolved into red algae and green algae Land plants are descended from the green algae Archaeplastida is the supergroup that includes red algae, green algae, and land plants |
|
Illustrate the divergences of red algae, green algae, and land plants.
|
|
|
Red AlgaeRed algae are reddish in color due to an accessory pigment called...
The color varies from greenish-red in... Red algae are usually multicellular; the largest are... Red algae are the most... |
Red Algae Red algae are reddish in color due to an accessory pigment called phycoerythrin, which masks the green of chlorophyll The color varies from greenish-red in shallow water to dark red or almost black in deep water Red algae are usually multicellular; the largest are seaweeds Red algae are the most abundant large algae in coastal waters of the tropics |
|
Give three examples of red algae.
|
|
|
Green Algae
Green algae are named for... Plants are descended from... The two main groups are the... Charophytes are most closely related to... |
Green Algae Green algae are named for their grass-green chloroplasts Plants are descended from the green algae Green algae are a paraphyletic group The two main groups are the charophytes and the chlorophytes Charophytes are most closely related to land plants |
|
Larger size and greater complexity evolved in chlorophytes by:
The formation of colonies... The formation of true multicellular... The repeated division... |
Larger size and greater complexity evolved in chlorophytes by: The formation of colonies from individual cells The formation of true multicellular bodies by cell division and differentiation (e.g., Ulva) The repeated division of nuclei with no cytoplasmic division (e.g., Caulerpa) |
|
Give two examples of Green Algae
|
|
|
Most chlorophytes have complex life cycles...
|
Most chlorophytes have complex life cycles with both sexual and asexual reproductive stages
|
|
Illustrate the complex life cycle of the Chlorophyte, with both sexual and asexual reproductive stages.
|
|
|
Concept 28.5: Unikonts include protists that are closely related...
The supergroup Unikonta includes... This group includes two clades: the... The root of the eukaryotic tree remains... It is unclear whether unikonts separated from other eukaryotes... |
Concept 28.5: Unikonts include protists that are closely related to fungi and animals The supergroup Unikonta includes animals, fungi, and some protists This group includes two clades: the amoebozoans and the opisthokonts (animals, fungi, and related protists) The root of the eukaryotic tree remains controversial It is unclear whether unikonts separated from other eukaryotes relatively early or late |
|
Illustrate the questionable phylogeny of Unikonta.
|
|
|
Amoebozoans
Amoebozoans are amoeba that have... They include... |
Amoebozoans Amoebozoans are amoeba that have lobe- or tube-shaped, rather than threadlike, pseudopodia They include slime molds, tubulinids, and entamoebas |
|
Slime Molds
Slime molds, or mycetozoans, were once... DNA sequence analyses indicate that the resemblance between slime molds... Slime molds include two lineages... |
Slime Molds Slime molds, or mycetozoans, were once thought to be fungi DNA sequence analyses indicate that the resemblance between slime molds and fungi is a result of convergent evolution Slime molds include two lineages, plasmodial slime molds and cellular slime molds |
|
Plasmodial Slime Molds
Many species of plasmodial slime molds are brightly... |
Plasmodial Slime Molds Many species of plasmodial slime molds are brightly pigmented, usually yellow or orange |
|
Illustrate the life cycle of Plasmodial slime molds.
|
|
|
At one point in the life cycle, plasmodial slime molds form a mass...
The plasmodium is not... It is undivided by plasma membranes and contains... It extends pseudopodia through... |
At one point in the life cycle, plasmodial slime molds form a mass called a plasmodium (not to be confused with malarial Plasmodium) The plasmodium is not multicellular It is undivided by plasma membranes and contains many diploid nuclei It extends pseudopodia through decomposing material, engulfing food by phagocytosis |
|
Cellular Slime Molds
Cellular slime molds form multicellular... Cells feed individually but can aggregate... Dictyostelium discoideum is an experimental model... |
Cellular Slime Molds Cellular slime molds form multicellular aggregates in which cells are separated by their membranes Cells feed individually but can aggregate to migrate and form a fruiting body Dictyostelium discoideum is an experimental model for studying the evolution of multicellularity |
|
Illustrate the life cycle of cellular slime molds.
|
|
|
Tubulinids
Tubulinids are a diverse group of amoebozoans with... They are common unicellular... Most tubulinids are... |
Tubulinids Tubulinids are a diverse group of amoebozoans with lobe- or tube-shaped pseudopodia They are common unicellular protists in soil as well as freshwater and marine environments Most tubulinids are heterotrophic and actively seek and consume bacteria and other protists |
|
Entamoebas
Entamoebas are parasites... Entamoeba histolytica causes... |
Entamoebas Entamoebas are parasites of vertebrates and some invertebrates Entamoeba histolytica causes amebic dysentery, the third-leading cause of human death due to eukaryotic parasites |
|
Opisthokonts
Opisthokonts include... |
Opisthokonts Opisthokonts include animals, fungi, and several groups of protists |
|
Concept 28.6: Protists play key roles in ecological...
Protists are found in diverse... Protists play two key roles in their habitats... |
Concept 28.6: Protists play key roles in ecological communities Protists are found in diverse aquatic and moist terrestrial environments Protists play two key roles in their habitats: that of symbiont and that of producer |
|
Symbiotic Protists
Some protist symbionts benefit... Dinoflagellates nourish... Wood-digesting protists inhabit... |
Symbiotic Protists Some protist symbionts benefit their hosts Dinoflagellates nourish coral polyps that build reefs Wood-digesting protists inhabit the gut of termites |
|
Some protists are parasitic
Plasmodium causes... Pfiesteria shumwayae is a... Phytophthora ramorum causes... P. infestans causes... |
Some protists are parasitic Plasmodium causes malaria Pfiesteria shumwayae is a dinoflagellate that causes fish kills Phytophthora ramorum causes sudden oak death P. infestans causes potato late blight, which contributed to the Irish famine of the 19th century |
|
Photosynthetic Protists
Many protists are important... In aquatic environments, photosynthetic protists and prokaryotes are... In aquatic environments, photosynthetic protists are limited... These populations can explode... |
Photosynthetic Protists Many protists are important producers that obtain energy from the sun In aquatic environments, photosynthetic protists and prokaryotes are the main producers In aquatic environments, photosynthetic protists are limited by nutrients These populations can explode when limiting nutrients are added |
|
Biomass of photosynthetic protists has declined as...
Growth of phytoplankton communities relies on... Warm surface water acts as... |
Biomass of photosynthetic protists has declined as sea surface temperature has increased Growth of phytoplankton communities relies on nutrients delivered from the ocean bottom through the process of upwelling Warm surface water acts as a barrier to upwelling |
|
If sea surface temperature continues to warm due to global warming, this could have large effects on...
|
If sea surface temperature continues to warm due to global warming, this could have large effects on: 1. Marine ecosystems 2. Fishery yields 3. The global carbon cycle |
|
Illustrate basic sea surface temperatures across the globe.
|
|
|
Living Small
Even a low-power microscope can reveal a great variety of organisms in a drop of pond water Protist is the informal name of... Protists constitute a... Protista is no longer... |
Living Small Even a low-power microscope can reveal a great variety of organisms in a drop of pond water Protist is the informal name of the group of mostly unicellular eukaryotes Advances in eukaryotic systematics have caused the classification of protists to change significantly Protists constitute a polyphyletic group, and Protista is no longer valid as a kingdom |
|
Illustrate a phylogeny, beginning with the last common ancestor of Excavata, SAR clade, Archaeplastida, and Unikonta.
|
|
|
Illustrate the general divergence of Excavata.
|
|
|
The 5 domains of life are... These 5 domains came from... |
|