Protists

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Protists
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Protist Characteristics

• Live in water
• Eukaryotic
• Most are unicellular, some are multicellular
  (algae)

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Protist Characteristics

• Some are autotrophic (can make own food) some
  are heterotrophic (cannot make own food)

Photosynthetic euglena
Amoeba eating paramecium (other protist)
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Protist Characteristics

• All can reproduce asexually (by mitosis or binary
  fission) some are capable of sexual reproduction
  (by conjugation)
• (Remember the different methods of asexual
  sexual reproduction?)

Asexual Reproduction Sexual Reproduction
Binary fission Sexual intercourse
Budding Pollination
Regeneration
Fragmentation
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Sexual or Asexual?
conjugation
Binary fission
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Protist Characteristics

• Some have cells with contractile vacuole that
  help maintain homeostasis (can hold and expel
  fluid)

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Protists can be

• Animal-like (protozoa) absorb or gather/capture
  food
• Flagellates (or zooflagellates)- move by
  flagella
• Examples ones that live in termite intestines,
  ones that cause African Sleeping Sickness

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African Sleeping Sickness
2. The protist multiplies among red blood cells,
and spreads throughout the body via the
bloodstream.
1. Tsetse fly carries the parasitic protist
inside, and infects the host when it bites,
allowing the protist into the bloodstream.
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More Animal-like Protists

• Sarcodines- uses pseudopods to move and capture
  prey
• Example amoeba
• (pseudo means false, pod means foot)
• http//micro.magnet.fsu.edu/moviegallery/pondscum/
  protozoa/amoeba/index.html
• Brain-Eating Amoeba!

http//www.foxnews.com/story/0,2933,399262,00.html

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More Animal-like Protists

• http//micro.magnet.fsu.edu/moviegallery/pondscum/
  protozoa/paramecium/index.html

• Ciliates- move/eat by cilia, has oral groove and
  anal pore
• Example paramecium

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More Animal-like Protists

• Sporozoans- parasitic, reproduces by spores
• Example plasmodium (causes malaria)

Plasmodium falciparum is carried by mosquitos,
and injected into the host when they bite.
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Protists can be

• Plant-like (algae)- contain chlorophyll and are
  photosynthetic
• Euglena- can make and consume food

http//micro.magnet.fsu.edu/moviegallery/pondscum/
protozoa/euglena/rostrifera/index.html
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More Plant-like Protists

• Diatoms- various shapes, cell walls of silicon,
  are used in toothpaste and scouring products

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More Plant-like Protists

• Dinoflagellates- have flagella one example
  causes red tides

Pfiesteria piscicida causes red tides and fish
kills
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More Plant-like Protists

• Multicellular algae- green, brown, red

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Protists can be

• Fungus-like- cell walls, absorb nutrients,
  reproduce by spores
• Slime molds
• Watermolds
• Example Phytophthora infestans cause of potato
  famine in Ireland (1845 1852)