► Chapter 28~ The Origins of Eukaryotic Diversity

Protists ► Ingestive (animal-like); protozoa ► Absorptive (fungus-like) ► Photosynthetic (plant-like); alga

The Endosymbionic Theory ► Mitochondria and chloroplasts were formerly from small prokaryotes living within larger cells

Diplomonads and Parabasalids ► Lack plastids ► No mitochondrial DNA, electon transport chains, or enzymes that are needed for the citric acid cycle ► Produce cofactors that are involved in ATP production in the cytosol. ► Most found in anaerobic environments

Diplomonads ► Two nuclei ► Multiple flagella ► Ex. Giardia intestinalis- through contaminated water

Parabasalids ► Include protists called trichomonads ► Trichomonas vaginalis- travels along reproductive and urinary tract of hosts caused infection

Euglenozoans ► Diverse clade that includes heterotrophs, photosynthetic autotrophs, and pathogenic parasites ► Main feature-spiral or crystalline rod of unknown function inside flagella ► Kinetoplastids and Euglenoids

Kinetoplastids ► Single mitochondrion that contains organized mass of DNA ► Include free living consumers of prokaryotes in freshwater, marine, and most terrestrial ecosystem as well as species that are parasitic ► Trypanosoma cause sleeping sickness in humans which is spread by the tsetse fly

Euglenids ► Have a pocket at one end from which a flagella emerges ► Use paramylon as a storage polymer ► Can be autotrophic or heterotrophic depending on conditions

Alveolates ► Characterized by membrane bound sacs just under the plasma membrane  Function unknown ► 3 groups  Dinoflagellates  Apicomplexans  Ciliates

Dinoflagellates ► In freshwater and marine water ► Most are unicellular ► Episodes of explosive population growth cause RED TIDES  Toxins that are produced by these dinoflagellates cause massive fish kills and invertebrate kills  Humans can also be affected if we consume organisms that have ingested the toxin

Apicomplexans ► Parasites of animals ► Spread through tiny infectious cells called sprozoites ► Named after complex of organelles that is specialized for penetrating host cell ► Ex. Plasmodim is spread by the anopheles mosquito in humans- causes malaria

Cilliates ► Varied group named after the use of cilia ► Usually reproduce asexually through binary fission but can promote genetic variation through conjugation

Stramenopiles ► Contain several groups of heterotrophs and algae ► Stamen refers to the numerous fine, hairlike projections which are a characteristics of these protisits ► Groups  Oomycetes, diatoms, golden algae, brown algae

Oomycetes ► Water molds, white rusts, downy mildews ► Very similar to and are thought to once have been fungi

Diatoms ► Unicellular algae that have a glass like wall made of hydrated silica embedded into an organic matrix ► 100,000 living species ► Major components of phytoplankton that make up the bottom of aquatic food chains

Golden algae ► Named after color which results from their yellow and brown carotenoids ► Typically biflagellate cells ► Can be autotrophic or mixotrophic

Brown Algae ► Largest and most complex algae ► All are multi-cellular and most are marine ► Include groups commonly called seaweeds and kelps

Rhodophyta ► Red algae ► no flagellated stages ► Phycoerythrin (red) pigment ► Can range in color from red to black to green depending on area they live

Chlorophyta ► Green algae- named after green chloroplasts ► Chloroplasts ► Gave rise to land plants ► Ex. volvox, ulva

Amoebozoans ► Have pseudopodia ► Include Gymnamoebas, entameobas, slime molds Gymnamoebas and entameobas ► Gymnamoebas- free living in water and soil ► Entameobas- parasitic that infect all classes of invertebrates and vertebrates

Slime molds Plasmodial and cellular slime molds ► Plasmodial molds- Mass of cytoplasm not divided by membranes ► Cellular slime molds- mass of cells but retain their individuality