micro chapter 5

• Eukaryotic Microorganisms


  Organisms that have a true nucleus and membrane-bound organelles
• Endosymbiosis Theory


  • Eukaryotes arose when a much larger cell incorporated smaller cells that began to live there rather than being destroyed
  • Molecular techniques show relationships between the organelles of eukaryotic cells and the structure of bacteria
• Eukaryotes originated approximately 2 billion years ago
• Archaea


  • Cells have a flexible outer envelope and mesosome-like internal membranes
  • Evolved from prokaryotes by a process of intracellular symbiosis
• Eukaryotes (Domain Eukarya)


  • Include microbes: Fungi, Algae and protozoa
  • Cell structure enabled them to diversify from single cells into a huge variety of complex multicellular forms
• Cell walls


  • Fungi have cell walls composed of chitin or cellulose
  • Algae have cell walls with a different composition
• Organelles in eukaryotic cells


  • Mitochondria, chloroplasts, ribosomes, nucleolus, cytoskeleton, golgi complex, lysosomes
• Phagocytosis


  Ingestion of material by an eukaryotic cell either to destroy foreign matter or for its own nutrition
• Reproduction of microscopic eukaryotes


  • Asexual by mitosis
  • Sexual by meiosis
• Types of fungi


  • Unicellular, microscopic fungi (molds and yeasts)
  • Multicellular, macroscopic fungi (mushrooms, puffballs, and other fungal structures)
• Hyphae


  Long, hair-like or web-like structures that are septated (divided by cross-walls)
• Mycelium


  The woven, intertwining mass of hyphae that makes the colony of a mold
• Types of asexual spores

  • Sporangiospores
  • Conidia (most common asexual spores in nature)
  • Arthrospores (rectangular)
  • Chlamydiospores (spherical)
  • Blastospores (formed by budding)
  • Phalospores (vase-shaped)
• Sexual reproduction in fungi

  Involves the fusion of fertile hyphae or two different male and female cells, and the development of special fruiting structures
• Types of sexual spores

  • Zygospores (fusion of hyphae to form zygote)
  • Ascospores (formed in asci)
  • Basidiospores (formed on the outside of basidia)
• Fungal phyla


  • Zygomycota (Phycomycetes)
  • Chytridiomycota
  • Ascomycota (Ascomycetes)
  • Basidiomycota (Basidiomycetes)
  • Deuteromycota (Fungi Imperfecti)
• Most fungi are saprobes that degrade dead plants or animals
• Fungi are important in agriculture, food, and pharmaceutical industries
• Fungi are found everywhere and can survive in environmental extremes
• Some fungi are infectious to plants, humans, and animals
• Kingdom Protista


  Subkingdom Algae
• Algae


  • Unicellular (microscopic or could form chains (filamentous))
  • Lack specialized tissues
  • Few have plant-like bodies called thalli
  • Photosynthetic and photic (light zone of water)
  • Mostly aquatic, plankton (cool temperature water)
  • Multicellular
  • Length from mm to 100m
  • Cell walls with Cellulose
  • Reproduce asexually by fragmentation, binary fission, and mitosis
  • Motile Spores (flagellum)
• Groups of Algae


  • Euglenophyta (Euglenoids)
  • Pyrrophyta (Dinoflagellates)
  • Chlorophyta (Green Algae)
  • Chrysophyta (Diatoms or Golden Brown Algae)
  • Phaeophyta (Brown Algae or kelps)
• Euglenophyta (Euglenoids)


  • Unicellular and flagellated
  • Move and feed using flagella
  • Have Chlorophyll, carotenoids, and Xanthophyll
  • Found deeper in ocean waters
• Pyrrophyta (Dinoflagellates)


  • Unicellular, flagellated
  • Atypical cell walls
• Chlorophyta (Green Algae)


  • Unicellular, colonial filamentous, and multicellular organisms
  • Cellulose
  • Chlorophyll (a,b), Carotenoids, and Xanthophylls
  • Store starch
  • Precursor of higher plants
• Chrysophyta (Diatoms or Golden Brown Algae)


  • Unicellular, filamentous forms
  • Cell wall with silicon dioxide
  • Chlorophyll and fucoxanthin
  • Major component of plankton
  • Store oil
  • Much of the World's petroleum was formed from diatoms that lived over 300 million years ago
• Phaeophyta (Brown Algae or kelps)


  • Multicellular with vascular system
  • Macroscopic and up to some length!
  • Walls with cellulose and alginic acid
  • Chlorophyll, Carotenoids, and fucoxanthin
  • Source of emulsifiers, alginate
  • Phenomenal growth rates up to 120 cm/day
• The top few meters of any body of water contain planktonic algae
• 314% of Earth is covered with water (80% of Earth's photosynthesis is carried out by algae)
• When diatoms and other planktonic organisms grew millions of years ago and died, the organic molecules they contain did not decompose to evolve CO2. Heat and pressure from geological processes altered oil and other elements were eliminated, leaving a residue of hydrocarbons in the form of petroleum and natural gas deposits.
• Subkingdom Protozoa


  • Microscopic, most are harmless, some pathogenic
  • Spread from host to host by insect vectors
  • Belong to Kingdom of Animalia
• Types of Protozoa


  • Mastigophora (Flagellata or Zoomastigophora)
  • Sarcodina (Amebas)
  • Ciliophora (Ciliates)
  • Apicomplexa (Sporozoans)
• Mastigophora (Flagellata or Zoomastigophora)

  • Asexual reproduction by fission
  • Sexual reproduction or by asexually by fission
  • Most are free-living and non-infectious
• Sarcodina (Amebas)


  • Move by pseudopods, some are flagellated
  • Single nucleus
• Ciliophora (Ciliates)


  • Most have mouth and feeding organelle
  • Majority are free-living and harmless
  • Asexual reproduction by fission
  • Lack Mitochondria and Golgi apparatus
• Apicomplexa (Sporozoans)


  • Parasitic organisms, no motility
  • Complex life cycles with sexual and asexual
  • Produce spore-like cells called sporozoites
• Entamoeba histolytica causes amoebiasis, Naegleria fowleri occurs free-living in hot water, Trypanosoma and Leishmania are blood pathogens spread by vectors, Giardia lamblia is involved in intestinal diseases, Trichomonas vaginalis is transmitted via sexual contact
• Subkingdom Animalia - Helminth Parasites

  • Multicellular animals equipped with organs and organ systems
  • Have reproductive tract, digestive, excretory, nervous, and muscular systems
  • Adult animals can be seen with the naked eye
• Groups (Phyla) of Helminths

  • Flatworms (Platyhelminths)
  • Roundworms (Aschelminthes)