Domain Eukarya Kingdom Plantae Phylum Chlorophyta Green Algae.
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Domain Eukarya Kingdom Plantae Phylum Chlorophyta Green Algae
Looking Back at Bio 115 The Organism as a Unit of Life Cellular Structure (cell = unit of life)…one or many! Metabolism = Homeostasis (PSN, Resp, N 2 fix, ferment, etc.) Growth = irreversible change in size Reproduction…failure = extinction Acclimatization-short term responses = behavior Adaptation-long term responses = evolution
Shifting Kingdoms Bacteria Archaebacteria Archezoans Euglenoids Chrysophytes Green Algae Brown Algae Red algae Slime Molds True Fungi Bryophytes Tracheophytes Protozoans Myxozoans Multicellular Animals Lumpers Splitters PlantaeProtistaPlantae
How Many Kingdoms? Multicellular Animals MyxozoansProtozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaebacteria Bacteria Original Cell Extant Extinct Long Time with Prokaryotes only Kingdom Plantae is a clade
Plants as a Clade Photosynthetic Organisms: Unifying features Cellulose walls glued together with pectin Chlorophyll a and b, xanthophylls, carotenoids Store starch Standard plant chloroplasts, mitochondria, golgi, etc. Most have Diplohaplontic (sporic) life history Most have Oogamous gametes
Chlamydomonas cells of opposite mating type join in syngamy to form a zygote which develops a thick wall as a hypnospore. Upon return to better conditions, the zygote undergoes meiosis and releases flagellated cells of both mating types.
SYNGAMY zygote SporophyteGametophyte sporangium sporocyte spores gametangia gametes germination mitosis differentiation mitosis germination mitosis 1N 2N differentiation MEIOSIS Life Cycle of Chlamydomonas r/Bilder/Chlamydomonas_spec_Zygote. jpg faculty/images/goodenoughca ption.jpg mmon/chlamydomonas.jpg r/Bilder/Chlamydomonas_spec_Zygote. jpg definitely zygotic (haplontic) is it gametic? (diplontic)
Ulva lactuca thallus
Ulva life cycle There are three isomorphic thalli: Some species of Ulva are anisogamous. Since they are motile, they are also called zoospores. The meiospores made by the sporophyte are of two mating types. + + – – 1N 2N zygote isogametes + – + – sporocyte GametophytesSporophyte syngamy meiosis settles on substrate settle on substrate holdfast The life cycle is: sporic: diplohaplontic gametic: diplontic zygotic: haplontic
Codium Life Cycle The life cycle is: sporic: diplohaplontic gametic: diplontic zygotic: haplontic 1N 2N syngamy anisogametes zygote sporangium sporocytes zoospores Sporophytes 2 sexes holdfast meiosis
Oedogonium Here the filaments are out of focus. The asexual zoospore is in focus.
Oedogonium This is the zoospore, or maybe it is the sperm. Both have the same look! When both oogonium and antheridium appear on the same filament the alga is homothallic.
Oedogonium Life Cycle The zygote divides meiotically to release 4 zoospores. Since antheridia and oogonia are on the same filaments, this species is homothallic. This life cycle is haplontic (zygotic). 1N 2N syngamy meiosis zygote (hypnospore) (in oogonium) Zoospores settle down with a holdfast and grow into a filament. sperm chemotaxis egg (in oogonium) Vegetative zoospores can clone the gametophyte empty antheridia