Chp 2

• Unikonts


  Members of a taxonomic supergroup that includes the Amoebozoa and its sister clade, the Opisthokonta, which includes the Fungi, Animals and the Choanomonada, or Choanoflagellates

  
• Eukaryotic cells of Unikonts

  Have a single emergent flagellum, or are amoebae with no flagella
• Amoebozoa


  • A major taxonomic group containing about 2,400 described species of amoeboid protists, often possessing blunt, fingerlike, lobose pseudopods and tubular mitochondrial cristae
• Plasmalemma


  Thin, elastic external cell membrane that retains the protoplasm within the cell and permits the passage of water, oxygen and carbon dioxide
• Ectoplasm


  Rigid external layer, a plasmagel without organelles
• Endoplasm


  Fluid internal layer in which streaming movements are visible
• Contractile vacuole


  Spherical structure that regulates osmotic pressure
• Food vacuoles


  Contain food in process of digestion
• Amoeboid locomotion


  1. Endoplasm flows forwards and the ectoplasm runs backwards along the outside of the cell

  2. Cell mass flows into a leading pseudopod, and the others ultimately retract, unless the organism changes direction
• Lobose pseudopods


  • Blunt, fingerlike
• Filopods


  • Composed only of ectoplasm
• Reticulopods


  • Similar to filopods, but interconnected as mesh
• Axopods


  • Without axonemes, but with spiraled microtubules, used only to ingest food
• Subphylum Lobosa


  Amoebae that have lobose pseudopods but lack cilia or flagella
• Order Tubilinidae


  Naked amoebas with an asymmetrical body and lobopods, living in fresh water and soil, reproducing asexually by budding and binary fission
• Order Arcellinidae


  Shelled amoebas that form rigid shells, or tests, equipped with a single aperture through which the pseudopods emerge
• Subphylum Conosa


  Grouping of Amoebozoa, subdivided into Mycetozoa and Archamoebae
• Archamoebae


  Distinguished by the absence of mitochondria, including genera that are internal parasites or commensals of animals
• Opisthokonta


  Broad group of eukaryotes, including both the animal and fungus kingdoms, with one flagellum at some stage in their life history

  
• Holozoa


  Group of organisms that includes animals and their closest single-celled relatives, such as choanoflagellates
• Choanoflagellates


  • Free-living unicellular and colonial flagellate eukaryotes, considered to be the closest living relatives of the animals, with a funnel shaped collar of interconnected microvilli at the base of a flagellum
• Metazoa


  Multicellular eukaryotic organisms of the kingdom Animalia, motile and heterotrophic, divided into vertebrates and invertebrates

  
• Non-bilaterian animals


  Porifera, Placozoa, Ctenophora, Cnidaria, have only two main germ layers (ectoderm and endoderm)
• Bilaterian animals


  Bilaterally symmetric, with a triploblastic body plan and a complete digestive tract with a mouth and anus, further divided into deuterostomes and protostomes
• Deuterostomes


  Differ from protostomes in that the first opening of the gut (blastopore) develops into the anus, and they undergo radial cleavage during cell division
• Protostomes


  The first opening of the gut (blastopore) develops into the mouth, and they undergo spiral cleavage during cell division