Topic 12: Diversity of Protists Flashcards

• what are the four major groups of Eukaryotes

  -excavates-SAR-Archaeplastida-Unikonts
• what is included in the Excavates eukaryotic group


  includes unicellular protists with modified mitochondria and protists with unique flagella
• how is the SAR eukaryotic grouped

  SAR protists are grouped by DNA similarities
• how have the SAR eukaryotic group originated

  may have originated by a secondary endosymbiosis of a photosynthetic red alga. Plastid later lost on some descendant SAR lineages.
• what does the archaeplastida eukaryotic group include

  includes red algae and green algae and they are the closest relatives to land plants
• what does the Unikonts eukaryotic group include

  includes protists that are closely related to fungi and animals
• what are the characteristics of the eukarya that belong to the Excavata clade (5)

  -protists with modified mitochondria or unique flagella-unicellular: variety of free-living and symbiotic forms, including predatory and photosynthetic species-some are important parasites of humans-share characteristic cytoskeleton morphology-some have an excavated feeding groove
• what are the three clades that make up Excavata

  -diplomonads-parabasalids-euglenozoans
• what are the characteristics of diplomonads and parabasalids in the excavata clade (5)

  -lack plastids-modified mitochondria-live in anaerobic enviornments-derive energy anaerobically-often parasites
• what does the euglenozoans clade of excavata include (5)

  -includes predatory heterotrophs, photoautotrophs, and parasites-kinetoplastids-euglenids
• what are the characteristics of the euglenozoans clade of excavata (1)

  spiral or crystalline rod of unknown function inside flagella
• what is a kinetoplastid within the euglenozoans clade of excavata


  have a single mitochondrion with an organized mass of DNA called a kinetoplast
• what does a kinetoplastid include within the euglenozoans clade of excavata

  includes free-living species that are consumers of prokaryotes in freshwater, marine, and moist terrestrial ecosystems
• what is a euglenid within the euglenozoans clade of excavata


  -have one or two flagella that emerge from a pocket at one end of the cell
• some species of euglenids in the euglenozoans clade of excavata are what

  are mixotrophs, which means they are simultaneously autotrophs and heterotrophs
• what are the characteristics of the SAR eukaryotic group (2)

  -highly diverse-monophyletic
• SAR clade is controversial and is named for its three major sub clades which are:

  -Stramenopiles-Alveolates-Rhizarians
• what habitat do SAR protists dominate

  eukaryotic diversity in oceans
• what does the stramenopiles sub clade of SAR include (3)

  -diatoms-brown algae-oomycetes
• what sub clade has some of the most important photosynthetic organisms on earth

  Stramenopiles of the SAR clade
• what do most stramenopiles in the SAR clade have for at least part of their life cycle

  hair flagellum paired with a smooth flagellum
• what are diatoms in the sub clade stramenopiles in the SAR clade

  are unicellular algae with a unique two-part, glass-like wall of silicon dioxide.
• how do diatoms in the sub clade stramenopiles in the SAR clade reproduce

  asexually, and occasionally sexually.
• what classification of organisms form a major component of marine phytoplankton

  diatoms in the sub clade stramenopiles in the SAR clade
• diatoms in the sub clade stramenopiles in the SAR clade account for what percent of oceanic photosynthesis

  50%
• what are diatoms in the sub clade stramenopiles in the SAR clade important contributors to

  carbon sequestration
• what kind of algae is the largest and most complex

  brown algae
• what classification does brown algae belong to

  sub clade stramenopiles in the SAR clade
• what are characteristics of brown algae in the sub clade stramenopiles of the SAR clade (3)

  -multicellular-most are marine-algal body is plant-like but lacks true roots, stems, and leaves
• what does brown algae in the sub clade stramenopiles of the SAR clade include

  includes many species commonly called seaweeds-giant seaweeds called kelps live in deep parts on the ocean
• what does brown algae in the sub clade stramenopiles of the SAR clade share morphological similarities between

  between algae and plants have analogous structures
• what are characteristics of brown algae's in the sub clade stramenopiles of the SAR clade life cycle (2)

  -involved alternation of generations-alternation of multicellular haploid and diploid forms
• how does the life cycle of brown algae in the sub clade stramenopiles of the SAR clade work (3)

  -the diploid sporophyte produces haploid flagellated spores called zoospores-zoospores develop into haploid male and female gametophytes, which produce gametes-fertilization of gametes results in a diploid zygote, which grows into new sporophyte
• what do oomycetes in the sub clade stramenopiles of the SAR clade include

  -water molds-white rusts-downy mildews
• what were oomycetes in the sub clade stramenopiles of the SAR clade once classified as

  as fungi based on morphological studies
• what confirmed that oomycetes in the sub clade stramenopiles of the SAR clade were not closely related to fungi

  molecular systematics
• whats the difference between oomycetes in the sub clade stramenopiles of the SAR clade and fungi

  oomycetes cell walls are made of cellulose and fungi cell walls are made of chitin
• what are characteristics of oomycetes in the sub clade stramenopiles of the SAR clade

  -most are decomposers or parasites-have filaments (hyphae) that facilitate nutrient uptake
• what classification of organism cause the great famine in ireland

  oomycetes in the sub clade stramenopiles of the SAR clade
• What are the characteristics of alveolata in the SAR clade (1)

  -have membrane bounded sacs (alveoli) just under the plasma membrane