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Domain Eukarya

Domain Eukarya. Protists. Kingdom(s?):. Themes in the Evolution of Protists. Larger Cell Size Larger cells make possible the evolution of diverse structures and functions.

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Domain Eukarya

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  1. Domain Eukarya Protists Kingdom(s?):

  2. Themes in the Evolution of Protists • Larger Cell Size • Larger cells make possible the evolution of diverse structuresand functions. • Compartmentalization increases the available surface area in the interior of cells, easing food & waste transport in & out of the cell. Paramecium: a unicellular cilliate

  3. Themes in the Evolution of Protists • Locomotion • Pseudopods • Protists can be motile by means of cilia or flagella. Cilia Flagella 2 single microtubules 9 paired microtubules The structure of eukaryotic flagella and cilia is different than prokaryotic flagella

  4. Themes in the Evolution of Protists • Multicellularity Volvocales spp. range from unicellular to colonial to multicellular. Gonium Chlamydomonas Pandorina Volvox

  5. Some protists are clearly multicellular This green alga, called Coleochaete orbicularis, is multicellular. Its cells are packed tightly together and are differentiated in form and function.

  6. Themes in the Evolution of Protists • Meiosis and sexual reproduction • Meiosis makes eukaryotic sexual reproduction possible.

  7. Sexual reproduction produces genetic variability Fertilization A1 A2 A2A2 or A1A1 A1 A2 Offspring genotypes Gametes A1 A2 Meiosis A1 A2 Parental genotype

  8. Some protists may alternate between sexual and asexual reproduction Chlamydomonas (n) Gametes (n) (n) (n) SEXUAL REPRODUCTION ASEXUAL REPRODUCTION (2n) (n) Mature cell (n) SYNGAMY MEIOSIS Zygote Haploid Diploid

  9. Giardia lamblia, a diplomonad Giardiasis is a diarrheal illness sometimes known as “Traveler’s Disease”

  10. Group 2: Euglenozoa • Typically unicellular • Characteristic type of flagella (1-2 flagella) • Autotrophic, heterotrophic, or mixotrophic Euglena

  11. Group 2: Euglenozoa- Others • Trypanosomes- Parasitic • Trypanosoma brucei- • African Sleeping Sickness • Carried by Tsetse flies • Trypanosoma cruzii- • Chagas disease • South America • Leishmania spp. • Worldwide parasites • Transmitted by sandflies

  12. Group 3:Aveolata • Dinoflagellates • Primary producers in coastal areas • Armored cellulose walls • Two whip-like flagella Gonyaulax – red tide

  13. Group 3:Aveolata • Apicomplexans • All obligate Parasites • Plasmodium--> malaria • Mass of organelles at one end (penetrate the host) • Spore-forming

  14. Group 3:Aveolata Paramecium • Ciliates • Cilia- short hair-like flagella used for feeding and moving • Oral groove • Multi-nucleate • Reproduce by fission and conjugation Stentor

  15. Group 4:Stramenopila • Oomycotes (water molds) • Fungi-like heterotrophs • Most live in fresh water or moist soil where they are important decomposers of plant detritus Downy mildew Potato Blight and the Irish Potato famine

  16. Group 4:Stramenopila • Diatoms • Glass cell walls • Major component of marine plankton • Major contributor to marine photosynthesis • Sediment to form diatomaceous earth

  17. Algae: Plant-like Protists • Algae are AUTOTROPHIC Protists- they perform PHOTOSYNTHESIS. • Often called “seaweeds”= brown, red, green algae Red: chlorophyll a and phycobilins Green: chlorophyll a and chlorophyll b Brown: chlorophyll a and chlorophyll c

  18. Algae: Plant-like Protists • Algae are Different from Plants because they LACK Tissue Differentiation and have No True Roots, Leaves or Stems.

  19. Group 5:Rhodophyta • Red Algae • No flagellated stages • Color from phycoerythrin • Often used to make cosmetics, gelatin capsules, agar

  20. Group 6:Chlorophyta • Green Algae • Not monophyletic • Closely related to plants • common ancestor of green algae and plants--> chloroplasts through endosymbiosis of cyanobacteria • mostly freshwater • Unicellular, colonial, multicellular

  21. Group 8:???? • Hodge-podge of organisms with unknown phylogeny • Use pseudopods for moving and feeding • Rhizopods (Amoeba) • Actinopods • Foraminifera Phagocytosis in Amoeba

  22. Amoeba have complex life cycles

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