Diversity of Protists Flashcards
4 groups of protists
excavate, SAR, Archaeplastida, Unikonta
Excavata
include unicellular protists with modified mitochondria and protists with unique flagella
Excavates traits
unicellular, predatory and photosynthetic forms, parasites for humans, share characteristic cytoskeleton morphology, have a feeding groove, some have euglenozoans, many have modified mitochondria
euglenozoans
unique flagella structures
Three clades included in Excavata
diplomands, parabasalids, and Euglenozoans
Diplomonads and Parabasalids traits
unicellular, heterotrophic, flagellated, lack plastids, have modified mitochondria, live in anaerobic environments
Euglenozoans
− Includes predatory heterotrophs, photoautotrophs, and parasites. − Clade characterized by spiral or crystalline rod of unknown function inside flagella
Examples of Eulenozoans
Kinetoplastids and Euglenids
Kinetoplastids
have single mitochondrion containing a large mass of DNA called a kinetoplast
Euglenids
have one or two flagella that emerge from a pocket at one end of the cell, and some are mixotrophs
SAR group
a monophyletic group originating likely from endosymbiosis of a photosynthetic red algae
_____ protists dominate eukaryotic diversity in the oceans
SAR
Major subclades of SAR
Stramenopiles, Alveolates, and Rhizarians
stramenopiles
Photosynthetic organisms including: diatoms, brown algae, and oomycetes
Many stramenopiles are:
unicellular flagellates or produce flagellates in at least part of their life cycles
Diatoms
highly diverse unicellular algae that are major components of marine phytoplankton generate 20-50% of the global oxygen, are surrounded by a unique two-part glass-like wall of silica, and usually reproduce asexually
Stramenopiles
largest and most complex algae, brown algae, multicellular seaweeds, kelps, cell wall consists of polysaccharides cellulose and alginic acid, lack roots/stems/leaves
Similarities between plants and algae are ___
analogous structures
The lifecycle of most brown algae involves
alternation of generations
Oomycetes
filamentous, heterotrophic stramenopiles that can reproduce sexually and asexually
Most oomycetes are:
decomposers or parasites
Oomycetes have filaments called ____ that facilitate nutrient uptake
hyphae
Alveolates
characterized by membrane-bounded sacs called alveoli, which forms a continuous layer under the plasma membrane
Examples of alveolates
dinoflagellates, apicomplexans, and ciliates
Dinoflagellates
have two flagella and the alveoli support overlapping plates; include aquatic photoautotrophs, chemoheterotrophs, and mixotrophs
Apicomplexans
parasites of animals and some cause serious human disease
Sporozoites
Infectious cells spread by alveolates
Apicomplexans have an ____ that contains a complex of organelles specialized for penetrating host cells and tissues
apex
Lifecycle stages in apicomplexans
Most apicomplexans have sexual and asexual stages that require two or more different host species to complete their life cycle
Plasmodium
An apicomplexan that causes malaria
Ciliates
a group of protists that use cilia to move and feed, are heterotrophs that feed on bacteria and protists by phagocytosis, and reproduce asexually but use conjugation to exchange haploid miconuclei
Rhizarians
mostly unicellular protists defined by DNA similarities,
Rhizarians have no ___ characteristics
morphological
Most Rhizarians are
amoebas (protists that move and feed
by extending and retracting pseudopodia,
extensions of the cell surface) which are not a monophyletic group
Archaeplastida
a photosynthetic supergroup that includes red algae, green algae, and land plants.
Archaeplastida have cell walls composed of ______
cellulose
Algae
photoautotrophic eukaryotes that are not members of the Kingdom Plantae
Algae form a ____ group
polypheletic
Algae include:
single-celled protists (diatoms and dinoflagellates) and multicellular forms (kelps and seaweeds)
Red algae
multicellular marine seaweeds that reproduce sexually, reddish in colour due to a photosynthetic accessory pigment (phycoerythrin)
Green Algae
Green pigments in chloroplast make algae green, with two main groups: chlorophyte and charophytes, most living in freshwater
Unikonta
heterotrophic protists that are closely related to fungi and animals
Unikonta includes two clades:
ameobozoans and Opisthokonts
Most unikont protists have a ________ or are amoebas with no _____
single emergent flagellum, flagella
Amoebozoans
a diverse group of amoeba that have lobe- or tubeshaped, rather than threadlike,
pseudopodia.
Amoebozoans have a very flexible body shape that:
move by extending blunt lobes (pseudopodia) and feed by phagocytosis
Amoebozoans include
Slime molds, tubliinids, and entamoebas
Two lineages in slime molds
plasmodial slime molds and cellular slime molds
Plasmodium
Plasmodial slime molds form a mass
Tubulinids
amoebozoans with lobe- or tube-shaped pseudopodia common in the soil as well as freshwater and marine environments
Entamoebas
pseudopodia-forming, intestinal
parasites of vertebrates and some invertebrates
