Kingdom Protista
Chapter 20
General Characteristics of
Protists:
• ALL Eukaryotes that cannot be classified
as a plant, animal, or fungus.
• They have a nucleus and membrane
bound organelles;
• some are autotrophic, some are
heterotrophic;
• some are multicellular, most are
unicellular.
They are classified by the way
they OBTAIN NUTRITION.
Three kinds of protists
• Animal-like (consume food)
• Plant-like (make their own food)
• Fungus-like (decomposer)
Animal-like Protists
• Called Protozoans- meaning “first animals”
• Examples:
– Zooflagellates
– Sarcodines
– Ciliates
– Sporozoans
Protozoans
• these are “Animal-like” protists that
consume their food (heterotrophs)
• Unicellular
• characterized by modes of locomotion
(how they move)
– Cilia
– Flagella
– Pseudopod
Zooflagellates
Trichomonas
• Characteristics: move by flagella (one or two)
• Reproduction: mostly asexual by mitosis, some
sexual reproduction- produce gametes that fuse
• Role/Function:
– Mostly free swimming
– Some are parasites
– Trypanosoma causes African Sleeping
Sickness, Giardia causes diarrhea
– Termites have a zooflagellate living inside
them that helps them digest wood
Zooflagellates
nucleus
flagella
Sarcodines
• Characteristics: move by pseudopodsextensions of cytoplasm
• Reproduction: asexually by mitosis
• Role/Function:
– free-swimming in aquatic environments Pseudopod
– Amebic dysentery (diarrhea)
Nucleus
Ameba proteus
Ciliates
• Characteristics:
– use cilia for movement and feeding
– Have a macronucleus (active nucleus) and
micronucleus (reserve copy)
• Reproduction: asexually by mitosis, can
exchange material through conjugation (Figure
20-6 in book)
• Role/Function: free-living
Paramecium
Ciliates
Cilia
Macronucleus
Micronucleus
Sporozoans
• Characteristics: Do not move on their
own
• Reproduction: complex reproduction with
two phases- a sexual phase and asexual
phase inside two different organisms!
• Role/Function:
– Parasitic
– Malaria is caused by the
sporozoan Plasmodium
Sporozoans
Nucleus
Plant-like (Algae)
• Unicellular
– Euglenophyta
– Chrysophyta
– Bacilliarophyta
(Diatoms)
– Pyrrophyta
(Dinoflagellates)
• Multicellular
– Rhodophyta
– Phaeophyta
– Chlorophyta
Unicellular Algae
• (describe their ecology/uses):
– autotrophic, capture sunlight with chlorophyll
and other accessory pigments to make food
– base of many aquatic food chains
• Example: phytoplankton- floating
photosynthetic organisms
Euglenophyta
• Characteristics: two flagella, no cell wall
• Reproduction: asexually by mitosis
• Role/Function:
– free-swimming
– can absorb material for food- recycling
sewage
– can lead to algal blooms choking
waters of nutrients
Euglenophyta
Chloroplast
Flagellum
Nucleus
Chrysophyta
• Characteristics:
– cell walls sometimes of pectin
– Gold-colored chloroplasts
• Reproduction: asexually and sexually
• Role/Function: free-floating
• Known as “golden algae”
Diatoms
• Characteristics: secrete thin cell walls of silica
(main component of glass)
• Reproduction: asexually and sexually
• Role/Function:
– Free-floating, or
– live in soil
Pyrrophyta-Dinoflagellates
• Characteristics: have two flagella and thick cell
wall
• Reproduction: asexually by mitosis
• Role/Function: responsible for red tides (algal
bloom of dinoflagellates that secrete toxins that
can cause illness paralysis, and death in fish
and humans)
Dinoflagellates
Nucleus
Flagella
Multicellular Algae
• (describe their ecology/uses)– Autotrophic
– Multicellular
– some have specialized tissue
– seaweeds and kelp
– used in foods such as sushi, ice cream, salad
dressing, candy, etc.
Red Algae (Rhodophyta)
• Characteristics: contain pigments- Chlorophyll
a and Phycobilins (red)
• Reproduction: sexually
• Role/Function:
– Deeper sea, great at harvesting
light
– Help form coral reefs
– Some used in foods and to make
agar
Brown algae (Phaeophyta)
• Characteristics: contain pigments Chlorophyll a
and c and Fucoxanthin (brown)
• Reproduction: sexually by mitosis and meiosis
• Role/Function:
– Form large habitats in aquatic
ecosystems
– Used some in food
Volvox- colonial
Green algae (Chlorophyta)
• Characteristics:
– unicellular, colonial, or multicellular
– chlorophyll a and b
• Reproduction: sexually by mitosis and
meiosis like true plants
• Role/Function: some form symbiotic
relationships with other organisms
Spirogyramulticellular
Ulvamulticellular
Alternation of Generations
Alternation of Generations
Kaikoura, New Zealand
Fungus-like
• Slime Molds
• Water Molds
Fungus-like
• (describe their ecology/uses):
– heterotrophic using external digestion to
break down dead and decaying organic
matter
Slime Molds
• Characteristics:
– cellular or acellular (masses with several
nuclei)
– Unicellular but can gather and act multicellular
• Reproduction: sexually
• Role/Function: Forest floor or compostingrecycle organic matter
Water Mold
• Characteristics:
– also called oomycetes (O-O-my-sets)
– Produce filaments called hyphae
• Reproduction: sexually and asexually
• Role/Function:
– dead decaying matter in aquatic environments
– some are plant parasites
– attack tomatoes and potatoes