Kingdom Protista

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Kingdom Protista

• Chapter 8
• Page 212

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Overview
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• Diverse group of organism
• Members of this group have little in common.
• This kingdom is artificial and used more for
  convenience
• Oldest fossils date back to 1.5 billion years

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General Characteristicsof Protists

• Organisms in this kingdom are eukaryotic
• Believed to have evolved from eubacteria
• Can be unicellular, colonial or multicellular
• o     colonial - of organisms living together
• o     multicellular- organism made of many cells
• Most but not all have flagella for movement
• Found in aquatic (water)environments
• Can be producers or consumers

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• There are 3 types of protists
• 1.    Plant/algal like protists
•        producers
• 2.    Animal like protists
•        consumers
• 3.    Fungal like protists
•       consumers
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1.Plant like Protists

• aquatic mainly fresh water
• all obtain energy by photosynthesis
• all contain chlorophyll (also found in plants)
  but these protist may not appear green due to the
  presence of pigments that mask(hide) the green
  color
• Reproduce both sexually and asexually

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Classification of Plant Like Algae

•  Plant like algae vary greatly, they are placed
  in their respective phylum's (6) according to
• 1.    the type of chlorophyll and accessory
  pigments they contain, that is their color
• 2.    the type of carbohydrate(sugar)/lipid they
  use to store energy
• 3.    the presence or absence of flagella.
• 4.    What the cell wall is built from.
• o      most contain cellulose but other compounds
  also found.

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Main Groups of Plant/Algal like Protists

• Group 1 Green Algae
• live mainly in fresh water
• due to large numbers can give pond water a green
  color( bloom)
• examples
• Unicellular- digitus
• colonial volvox
• multicellular spirogyra
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• reproduce asexually and sexually
• Scientist think green algae may have evolved into
  plants
• because they contain both chlorophyll ab like
  plants
• have cellulose in cell walls
• store energy as starch(like plants) Starch is a
  carbohydrate
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  Group 2-Diatoms

• have shells that contain silica
• they are microscopic
• unicellular, simple filaments (chain like) or
  colonies
• found in marine and fresh water
• Usually brown in color but they do contain
  chlorophyll.
• Producers

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Group 2-Diatoms Contd.

• Energy is stored as oil
• shells remain intact many years after organisms
  die. Shells have accumulated over millions of
  years to form diatomaceous earth
• Have industrial uses- in cleaning agents, tooth
  paste and as illuminating particles in road
  markings.

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Group 3- Brown Algae

• producers
• cell wall contains cellulose
• Energy storage as oil or unique carbohydrates.
• contain chlorophyll but its masked
• types of seaweed ex. kelp
• found in cooler regions and rocky shores, anchor
  to rocks

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• Brown seaweeds vary greatly in size
• Brown seaweeds are of economic importance they
  contain a substance called algin that is used as
  a thickening agent in the food industry
• Brown seaweeds can be differentiated(specialised)-
  air bladders

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Group 4-Golden Algae

• Golden algae
• producers found in many food webs ex. plankton
• provide a lot of worlds oxygen through
  photosynthesis
• have 1 or 2 apical flagella
• Plankton are small aquatic organisms floating or
  drifting on the surface of water, they play an
  extremely role in aquatic food webs
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Group 5-Dinoflagellata

• Microscopic
• Grow on sea surface- plankton
• Yellowish,green, brown reddish
• Tend to be unicellular
• Most have 2 flagella of unequal length
• Found in warm marine waters

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• Responsible for red tides
• Release toxins to shell fish that feed upon them
• More closely related to flagellates(animal like
  protist) than algae

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Group 6-RED ALGAE

• Are multicellular organisms and grow in warm
  Saltwater Habitats. 
• Besides Chlorophyll, Red Algae have other
  pigments, that trap sunlight. 
• They allow Red Algae to live in deep water where
  there is too little light for most other plants
  and algae.

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• Certain species of Red Algae have cell walls
  coated with a Sticky substance called CARAGEENAN
  used in the production of Cosmetics, Gelatin
  Capsules, and some types of Cheese.
• AGAR, which is used as a gel-forming base for
  culturing bacteria is extracted from the cell
  walls of Red Algae.

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Plant like Protists and the Environment

• They produce a lot of the worlds oxygen through
  photosynthesis
• Dinoflagellates pose a health threat to other
  marine organisms and humans red tides
• Blooms
• Important food source, bottom of aquatic food
  chains