Algae

• Algae


  Plant-like protists
• Algae is different from plants because:

  • has no roots, stems, or leaves
  • Gametes forming in unicellular chambers instead of multicellular
• Chlamydomonas


  Unicellular, single celled, aquatic algae
• Volvox


  Colonial, groups of cells working together, aquatic algae
• Spirogyra


  Filamentous, rows of cells, aquatic algae
• Ulva


  Multicellular, large and complex, aquatic algae
• Asexual chlamydomona :

  • Haploid cell absorbs its flagellum
  • Divides mitotically and generates zoospores which exit the cell when ready
• Sexual chlamydomona :

  • haploid cells divide into "plus" or "minus gametes"
  • They then fuse and form a diploid zygote
  • Zygote gets thick protective layer, becomes zygospore
  • When conditions = favorable, zygospore undergoes meiosis and becomes new haploid cells
• Antheridium


  Male unicellular gametangia of filamentous algae
• Oogonium


  Female unicellular gametangia of filamentous algae
• Filamentous algae reproduction

  • Antheridium produces sperm, oogonium produces egg
  • Zygote forms, thick walled resting spore
  • Diploid spore undergoes meiosis and forms 4 haploid zoospores
  • Zoospore released, settles, divides, forming new filament
• Conjugation


  When two filaments line up, create tunnels between them, have gametes flow through the tunnels, gamete forms thick wall and falls away from the parents, eventually becoming a new filament
• Phylum chlorophyta


  Green algae
• Phylum chlorophyta


  Filamentous, colonial, unicellular, and multicellular species, live in freshwater land, marine, cellulose, ancestors of land plants
• Phylum phaeophyta


  Brown algae
• Phylum rhodophyta


  Red algae
• Phylum rhodophyta


  All multicellular, mainly marine species (seaweed), carageenan and agar are extracted from these plants
• Phylym bacillariophyta


  Diatoms
• Phylum bacillariophyta


  Unicellular or colonial, component of phytoplankton, silica shells that fit like lids, when they die their shells accumulate and can be used in things like detergents
• Phylum phaetophyta


  All multicellular, mostly marine (seaweed or kelp), fucoxanthin gives them their color, air bubbles in blades lets them float for photosynthesis
• Phylum dinoflagellata


  Unicellular, 2 flagella of unequal length, creates red tides when they bloom, some are bioluminescent
• Phylum chrysophyta


  Gold algae
• Phylum chrysophyta


  Unicellular or colonial, freshwater, stores surplus as oil (petroleum deposits) and form resistant cysts under bad conditions
• Phylum euglenophyta


  Unicellular, freshwater, photosynthesize BUT can move themselves and dont have a cell wall