kingdom protista
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Kingdom Protista
Protists, What are they?
Protists are defined by what they are NOT…
Eukaryotes that are not plants, animals, or fungi
Scientists believe they were the “1st eukaryotic organisms”
Most are unicellular (algae exception) Many are “aquatic” Very diverse kingdom
Protists and the Evolutionary Tree
Animal-like Protist
Heterotrophic organisms Distinguished by how they move:
1) flagella: long “tail-like” structure2) pseudopods: “false feet”
extensions of cytoplasm 3) cilia: tiny “hair-like” structures
beat in unison 4) some immobile
Sarcodines Animallike protists
use pseudopods for feeding and moving
Ex) Amoeba
Food
Ciliates Animallike protists
use cilia for feeding and movement
Ex) Paramecium
Zooflagellates
Animallike protists swim using flagella
Trypanosoma protist spread by the bite of tsetse fly causes African Sleeping Sickness
Giardia can contaminate water and cause digestive problems
Trichonympha lives in mutualistic relationship with termites
Sporozoans
Animallike protists that do not move on their own and are parasitic
Plasmodium sporozoan causes malaria Sporozoan parasite is carried by female Anopheles
mosquito
Plasmodium Life Cycle Mosquito bites human
parasite injected• Parasites invade liver
reproduce and develop• Liver cells burst and
parasites move red blood cells
• RBC burst person experiences anemia, fever, chills, may result in death
• Parasites may then move into other RBC or are picked up by mosquito and transferred to another person
Plantlike Protists: Unicellular Algae
Photoautotrophs- contain chlorophyll and carry out photosynthesis
Often called “phytoplankton”- small photosynthetic organisms near the surface of ocean
Phytoplankton carries out photosynthesis releasing oxygen into the atmosphere
Phytoplankton important food source for many “filter feeders”
Euglenophytes
Plantlike protists that have flagella chloroplast, but no cell wall.
Ex) Euglena
Diatoms
Produce thin, delicate cell walls made of silicon
Used in toothpaste, paints on license plates, dynamite
Plantlike Protists: Algae
Red Algae- mostly multicellular algae contains special pigments that allows it to live deep areas of water
Brown Algae- all multicellular and most are found in marine environments (ex: Kelp)
Plantlike Protists: Algae
Green Algae- some are unicellular, some form colonies, few are multicellular
Chlamydomonas
Volvox
Sea Lettuce
Humans and Algae
• Humans understand many beneficial uses of algae:1) Used to make nutrient agar2) Used as ingredient in ice cream, pudding, salad dressing, syrups3) Food source – humans and other animals4) Releases oxygen from photosynthesis
• Algae causes harm in “algal blooms” – depletes water of nutrients and oxygen
Funguslike Protists
Heterotrophic protists that absorb nutrients, but lack cell walls with chitin
Ex) Slime molds- found near moist, rotting logs and composts
Ex) Water molds – can be parasitic and cause “ick” in fish