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Objective 1.1: Identify unicellular organisms, including bacteria & protists, by their methods of locomotion, reproduction, ingestion, excretion, and effects on other organisms.
Invention of the microscope led to discovery of unicellular organisms.
Advances in technology have led us to discover the good & bad of microorganisms, benefiting the world.
How we divide the unicellular organisms:
Organisms are put into domains & kingdoms based on 3 things:
Cell type: prokaryotes or eukaryotes
Ability to make food: heterotroph or autotroph
Number of cells in bodies: unicellular (1 cell) or multicellular (many cells)
3 Domains
Bacteria: prokaryotes (no nucleus), autotrophic or heterotrophic, microscopic
Archaea (Archeabacteria): prokaryotes (no nucleus), autotrophic or heterotrophic; microscopic; no cell walls; extreme environments (hot, cold, salty, acidic)
Eurkarya: eukaryotes, nucleus; in 4 kingdoms—protists, fungi, plants, or animals
Domain: Prokarya, Kingdom: Eubacteria
Many are decomposers that break down dead organisms & wastes.
Some are producers, making their own food
Use conjugation or binary fission to reproduce
Conjugation in E. coli bacteria
Here you can
conjugation—transfer
of genetic material
through a threadlike
bridge—it’s bacterial
sex.
http://www.google.com/imgres?imgurl=http://static.flickr.com/88/210973649_b75e67726a.jpg&imgrefurl=http://scienceblogs.com/mikethemadbiologist/2006/12/its_my_birthday.php&usg=__phZIkfzAulw0SJ50GgWwJ2R5QcM=&h=408&w=500&sz=72&hl=en&start=0&zoom=1&tbnid=jNjddxMGkYrSIM:&tbnh=143&tbnw=168&ei=Xja-TeTaEcL10gHC8LimBg&prev=/search%3Fq%3Dconjugation%2Bin%2Bbacteria%2B%252B%2Be%2Bcoli%26um%3D1%26hl%3Den%26rlz%3D1T4TSHB_enUS326US327%26biw%3D1419%26bih%3D756%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=126&vpy=86&dur=5402&hovh=203&hovw=249&tx=138&ty=94&page=1&ndsp=28&ved=1t:429,r:0,s:0
Binary fission in E. coli bacteria
asexual reproduction
in which the cell
basically copies itself
and undergoes cell
division—special type
of mitosis
http://scienceray.com/biology/microbiology/e-coli-bacteria/
Domain: Eurkarya, Kingdom: Protista (the protists)
CANNOT be classified as plant, animal, or fungus
“odds and ends” kingdom
Mainly unicellular others multicellular, so it is usually referred to as single-celled/unicellular
Classified by the way they get energy--some autotrophs others heterotrophs
Examples of Protists
Euglena: use flagella to move
Amoeba:Use pseudopods(false feet; cytoplasmicExtensions to move)
How protists like the Euglena and Amoeba reproduce
Both of these organisms reproduce asexually by binary fission—a special type of mitosis.
Can produce ENDOSPORES when conditions are bad, preventing the species from extinction.
Picture of a typical endospore, used by bacteria & protists
Remain dormant until conditions in the environment are favorable for development
An endosporeis a tough, resistantstructure used forsurvival during conditions not favorable for reproduction
Examples of Protists
ParameciumUse cilia—hair-like
projections around its body to move
Reproduce sexually by conjugation & asexually by binary fission.
Reproduce with endospores when times are bad.
Getting food & dumping wastes in protists
Animal-like protists ingest their food—the process is called ingestion—surrounding it with pseudopods or engulfing it and trapping it in a food vacuole for digestion, a process known as endocytosis.
http://www.ibiblio.org/virtualcell/textbook/chapter3/cmf4a.htm for endocytosis animation by amoebahttp://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio02.swf::Endocytosis%20and%20Exocytosis
Contractile vacuoles keep these single-celled animals from exploding due to excess water that collects in their cytoplasm due to osmosis. They collect the excess water & then excrete it—the process is called excretion.
All organisms dump wastes through this process
Exocytosis—think ex = exitthis is the process where unwanted materials in the cell are literally dumped out of the cell. this may be through contractile vacuoles, diffusion, or in more complex structures such as those of the paramecium, the anal pore.
http://www.ibiblio.org/virtualcell/textbook/chapter3/cmf4b.htm for exocytosis animation
Plant like protists: algae, producers
Domain Eukarya, Kingdom Fungi
Multicellular eukaryotes except yeasts which are unicellullar
Heterotrophs, can act as decomposers
Absorb nutrients to get energy
Cell walls present
Reproduce using endospores
Examples: molds, yeasts, mushrooms
Fungi Examples
Yeast (Candida albicans)
Fungi Examples
Bread mold, Rhizopus, the happy accident of penicillin
Examples of Fungal Spores
Mushroom spores
Toxic molds: Stachybotrys chartarum or Stachybotrys atra