Classification/Virus/Monera/Protista/Fungi Notes

 

Classification

Why classify organisms?

Taxonomy – science of classification

Aristotle – Plants and Animals (Structure and Size – subdivided by where they live)

Linnaeus – Binomial nomenclature – two part name (genus, species) [Acer rubrum or Acer rubrum]

Classify based on: structure, biochemistry and development, and molecular basis

Phylogeny – evolutionary history of an organism

Kingdom (most broad) – Phylum – Class – Order – Family – Genus – Species (most specific)

5 kingdom system – Monera – Protista – Fungi – Plants – Animals

 

Viruses – DNA core and a protein coat [Are viruses alive?]

Lytic cycle – virus takes over cell to make new viruses

Lysogenic cycle – virus encorporates its DNA into host DNA, eventually enters lytic cycle

Retrovirus – contains RNA – makes DNA copy of RNA – runs transcription in reverse DNA copy gets into host cell

 

Monera

Archaebactiera (ancient bacteria); Eubacteria (true bacteria)

Prokaryotic – no nucleus – no membrane bound organelles – have cell walls

Shape – rod (bacilli); sphere (cocci); spiral (spirilla); In cluster (staphylo…); In long chains (Strepto…)

Endospore – bacteria forms hard wall around DNA and some cytoplasm – hang out during rough conditions

Saprophytes – organism that feed on dead or decaying organisms, and recycle the nutrients

True Bacteria nutrition – heterotrophs; autotrophs (photosynthetic, chemotrophic)

Ancient bacteria – no oxygen – autotrophs (produce methane; love salt, heat and acid environments)

Importance – decomposers; food production; antibiotics

Examples:  (Ancient) thermoacidophiles; methanogens; / (True)  blue-green bacteria; spirochaetes

 

Protists

Animal-like:          Rhizopods – Amoeba (uses pseudopodia to move)

 (Protozoans)         Ciliates – Paramecium (uses cilia to move)

                                 Flagellates – Trypanosoma (African Sleeping Sickness) – mutualistism – 2 species live together both benefit

                                    (use flagella to move)

                                 Sporozoans – Plasmodium (Malaria) - don’t move – use sporelike structures for reproduction - parasites

 

Plant-like:             Euglenoids – Euglena – photosynthetic, but can become heterotrophic in the dark - unicellular

 (Algae)                  Golden algae - Diatoms - photosynthetic - unicellular

Red algae – Chondrus crispus – multicellular -  live in deep water – photosynthesis (blue light)

Brown algae – kelp, Sargassum – multicellular – photosynthesis – source of iodine; ice cream

Green algae – Ulva, Volvox, Spirogyra – multicellular - photosynthesis – sexual reproduction

 

Fungus-like:         Slime molds (cellular and plasmodial) – decomposers – forms plasmodium mass when bad conditions

Water Molds; Mildews; and Rusts are other examples – Potato Blight in Ireland; Ich on fish

Unicellular/multicellular stages; heterotrophic

 

Fungi

Structure – hyphae: thin filaments; mycelium: mat of filaments; spores: reproductive structure; all heterotrophic and multicellular (except yeast); 5 phyla; asexual and sexual except Imperfect Fungi (asexual only)

 

Zygote Fungi:      Rhizopus – bread mold; saprophytes; have rhizoids – special hyphae that anchor fungus

 

Club Fungi:          Mushrooms; puffballs; smuts; - have club shaped structure called: basidia – forms spores

                               The mushroom you see is the reproductive part; some poisonous

 

Sac Fungi:            Yeasts; morels; truffles; cup fungi; mildews; - have structure called ascus; produces sexual spores

                               Yeasts are unicellular; Special example is Penicillium mold – makes medicine and cheese

 

Lichens:                Dual organism – fungus + blue green bacteria or green alga; grow on rocks, soil, and trees

The green organism is autotrophic, providing food for itself and the fungus – fungus role unclear –protection and moisture?  Serve as food for animals; Create soil in rocky or barren regions.