Eukaryotes

• -some question the endosymbiotic origin (aka fusion hypothesis) as the main driver behind it
• -evidence from the PVC superphylum (superphyla of bacteria), which shares many features w/ Eukarya (and not necessarily w/ Archaea)
• -therefore this superphyla may have served as
• ancestrial "stock"
• -& the evolution of the many major features of
• Eukarya may have been present in some Bacteria
• & evolved in steps

• 1. Decomposers
• 2. Symbiotic relationships (mutualistic)
• ex: 500-1000 species in our intestines that help w/
• digestion

• 1. 1/2 of all human parasites are bacteria (deadliness caused by toxins)
• 2. Can be used as bioterrorism agents (ex: anthrax)
• 3. Difficult to defeat given rapid evolution

• 1. Fermentation for food
• 2. Research
• 3. Genetic modification & bioengineering
• 4. Bioremediation-remove pollutants from the environment (ex: oil spill in Gilf of Mexico)
• 5. Decomposers
• 6. Mutualistic symbiosis
• 7. Provide scenic landscapes
• 8. Oxygenation of the Earth

• -mainly unicellular
• -mainly aquatic
• -some asexual, some sexual, some both
• -they are all Eukaryotes

Endosymbiosis (process of engulfing cells that become endosymbionts & ultimately organelles/plastids)

One heterotrophic Eukaryote engulfs a photosynthetic cyanobacterium

Red or green algae being engulfed by another Eukaryote

• -Lack plastids
• -Mitochondria lack DNA

Spiral or crystalline rod at base of flagella

• A) Kinetoplastids (Trypanosoma)
• B) Euglenids (Eugela)
• -Photosynthesis or be heterotrophs

Red algae symbiont

Membrane bound sacs just under plasma membrane (unknown function)

ex: Dinoflagellates, Apicomplexans (Plasmodium-malaria), Cilliates (Paramecium)

• Hairy flagellum and smooth flagellum
• ex: Oomycetes, Golden Algae, Diatoms, Brown Algae

• -seaweed = some type of algae that have specialized tissues & "organs" like those seen in plants, but they have evolved independently
• ex: Alternation of generations
• Multicellularity & Tissue formation
• Larger in size w/ parts (holdfast, stipe, blades)

Move by threadlike psuedopodia

• A) Cercozoans (Forams-CaCO₃ shells)
• B) Radiolarians (SiO₂ shells)

• -amoebas w/ lobe shaped psuedopodia
• -these are thought to be the closest relative to the Fungi & Anamalia

ex: Gymnoamoebans, enamoebans & slime molds

• -Chlorophyll a
• -endosymbiotic event w/ a cyanobacterium--->led to chloroplasts

• -phycobillins
• -some "seaweeds"

• -Carotenoids
• -Chlorophyll b
• i. chlorophyta
• ii. charophyta (stoneworts)
• -sister group to plants

• 1. Similar percentage of cellulose in their cell walls
• 2. Peroxisome enzymes that minimize loss of organic
• products
• 3. Similar structure to their flagellated sperm
• 4. Similar chloroplast DNA
• 5. Formation of phragmoplast (scaffold for formation
• of the cell plate at the end of a miotic division