Chapter 28 Part A: Protists Flashcards
What gave rise to the great diversity of protists?
Endosymbiosis
Most eukaryotes are ______-celled organisms
Single
Is an informal term used to refer to all eukaryotes that are not plants, animals, or fungi
Protists
Why are protists no longer considered a kingdom?
Some protists are more closely related to plants, fungi, or animals than other protists
What are inside of the cells of protist and other eukaryotes?
Nucleus and other membrane-enclosed organelles
__________ isolate functions within ______ cells, making them more _______ than ________ cells.
Organelles, eukaryotic, complex, prokaryotic
What of the eukaryotic cell allows it to have asymmetric shape and to change shape overtime
Well-developed cytoskeleton
What make up much of the diversity of eukaryotes?
Protists
________ exhibit more _______ and _______ diversity than any other group of eukaryotes
Protists; structural, functional
T/F: There are only unicellular protist species
F: most are unicellular BUT some are colonial and multicellular
What type of protists are the most complex?
Unicellular
Why are unicellular protists the most complex?
Each cell must carry out all functions of life
Protists are the most _________ diverse of all eukaryotes
Nutritionally
What are 3 protists that are nutritionally diverse?
Photoautotrophs, heterotrophs, and mixotrophs
What do photoautotrophs contain?
Chloroplasts
Which nutritional protist absorb organic molecules or ingest larger food particles?
Heterotrophs
What do mixotrophs do?
Combine photosynthesis and heterotrophic nutrition
T/F: all protists reproduce asexually
F: SOME protists only reproduce asexually; others have both asexual and sexual phases in their life cycle
What are the three basic types of sexual life cycles represented among protists?
Animal, plant, and fungal
There is an abundant evidence that much of protistan diversity has its origins in
Endosymbiosis
A relationship between 2 species in which one organism lives inside the cell or cells of the other organism (host)
Endosymbiosis
What 2 organelles are derived from bacteria that were engulfed by ancestors of early prokaryotes?
Mitochondria and plastids
What evolved before plastids and arose from an alpha proteobacterium?
Mitochondria
_________ analysis indicates that mitochondria and plastids each evolved _______ in the history of life.
Molecular; once
The _________ host was a relatively complex cell with eukaryotic features, such as a ________
Ancestral; cytoskeleton
The host cell lineage is _______, but ____________, the archaea sister group to the ________, is a candidate ______.
Uncertain; lokiarchaeotes; eukaryotes; taxon
The evolution of ________ gave rise to the eukaryotes.
Mitochondria
________ arose later when a __________ eukaryotes engulfed a __________ cyanobacterium.
Plastids; heterotrophic; photosynthetic
Two lineages of ____________ protists _____ and _____ algae, evolved from the plastid bearing ancestor.
Photosynthetic; red; green
How many membranes do red and green algae have?
2
The red and green algae having two membranes is similar to what?
Cyanobacteria
___________ proteins in the red and green algae are ________ to those found in the inner and outer _______ of ____________.
Transport; homologous; membranes; cyanobacteria
Red and green algae were ingest by _________ eukaryotes, a process called _________ _________, several times.
Heterotrophic; secondary endosymbiosis
How many supergroups are eukaryotes divided into?
4
What are the 4 supergroups of eukaryotes?
Excavata, SAR, Archaeplastida, and Unikonta
Excavata includes how many clades?
3
What are the Excavata clades?
Parabasalids, diplomonads, and euglenozoans
What is an example of a diplomonad? What does it do?
Giardia intestinalis is a diplomonad parasite; causes intestinal infections in mammals
SAR includes how many clades?
3
What are the SAR clades?
Stramenopila, Alveolata, and Rhizaria
What is an example of a stramenopila?
Diatoms; important photosynthetic stramenopiles
What is an example of a rhizaria?
Amoebas; Globigerina
Red and green algae, and plants belong to which supergroup?
Archaeoplastida
Red and green algae include ________, _______, and _______ species.
Unicellular, colonial, multicellular
What is an example of a multicellular green algae?
Volvox
What are included in Unikonta?
Amoebas (with lobe- or tube- shaped pseudopodia), animals, fungi, and non-amoeba protist closely related to animals or fungi
What is an example of a tubulinid amoeba?
Amoeba proteus
T/F: The root of the eukaryotic tree is known
F: it is not known
What are the 3 supergroups that are unresolved?
Haptophytes, cryptophytes, and hemimastigophores
Excavates include protist with modified ________ and protist with unique ________
Mitochondria; flagella
Which supergroup is characterized by its cytoskeleton?
Excavata
The excavates include how many monophyletic groups?
3
What are the three monophyletic groups of excavates?
Diplomonads, parabaslids, and euglenozoans
Which two clades in Excavata lack plastids and have reduced mitochondria?
Diplomonads and parabasalids
Where do diplomonads and parabasalids live?
Anaerobic environments
What are reduced mitochondria of Diplomonads called?
Mitosomes
What do mitosomes lack?
Electron transport chains (ETC)
What is derived from anaerobic pathways?
Energy
What do Diplomonads and Parabasalids contain?
2 equal-sized nuclei and multiple flagella
What are the reduced mitochondria of the Parabasalids called?
Hydrogenosomes
What do hydrogenosomes generate? How do they generate it?
Some energy; anaerobically
What is released as a by-product of anaerobic metabolism?
Hydrogen gas
What is the best known parabasalid?
Trichomonas vaginalis
Euglenozoans include how many?
4
What are the 4 considered Euglenozoa?
Heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites
What is the main feature distinguishing the Euglenozoan clade?
A spiral or crystalline rod inside each flagella
Kinetoplastids and euglenids are included in which clade?
Euglenozoans
Kinetoplastids have how many mitochondria?
One
What is inside the Kinetoplastids mitochondrion?
Kinetoplast
An organized mass of DNA in a kinetoplastid’s mitochondrion.
Kinetoplast
Species of what parasitize animals, plants and other protists; example is Trypanosoma
Kinetoplastids
Have a single cell-surface protein that changes from one generation to the next
Trypanosomes
The host is prevented from developing immunity by this “bait-and-switch” defense
Kinetoplastids
Have one or two flagella that emerge from a pocket at one end of the cell
Euglenids