Post on 20-Jan-2018
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Kingdom ProtistaChapter 19
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)
19.2 Animal-like Protists TEKS 11C, 12A
KEY CONCEPT Animal-like protists are single-celled heterotrophs that can move.
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• 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
Trichomonas
nucleus
flagella
Zooflagellates
Sarcodines• Characteristics: move by pseudopods-
extensions of cytoplasm• Reproduction: asexually by mitosis• Role/Function:
– free-swimming in aquatic environments– Amebic dysentery (diarrhea)
Ameba proteus
PseudopodPseudopod
NucleusNucleus
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
Macronucleus
Micronucleus
Cilia
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
Nucleus
Sporozoans
19.3 Plantlike Protists TEKS 8B, 8C, 11C
KEY CONCEPT Algae are plantlike protists.
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
19.3 Plantlike Protists TEKS 8B, 8C, 11C
• Euglenoids are a large group of plantlike protists.
pellicle
nucleus
chloroplast
eye spot
contractilevacuole
flagellum
– mostly photosynthetic – some heterotrophic – single-celled – one or two flagella
Euglenophyta
Flagellum Nucleus
Chloroplast
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
19.3 Plantlike Protists TEKS 8B, 8C, 11C
• Diatoms are plantlike protists with glasslike shells. – shells made of silica – produce large amounts of oxygen
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 fishand humans)
19.3 Plantlike Protists TEKS 8B, 8C, 11C
• Dinoflagellates are mostly marine plantlike protists.
Dinoflagellates
– have two flagella – may be bioluminescent – have stiff protective plates – can cause red tide
DinoflagellatesNucleus
Flagella
19.3 Plantlike Protists TEKS 8B, 8C, 11C
• Multicellular algae are classified by their pigments.
– Green algae contain chlorophyll a and b. – Brown algae contain chlorophyll c. – Red algae contain chlorophyll a and phycoerythrin.
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
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
Spirogyra- multicellular
Volvox- colonial
Ulva- multicellula
r
19.3 Plantlike Protists TEKS 8B, 8C, 11C
• Some algae produce sexually. – Some species alternate generations.– Sexual reproduction can be triggered by environmental stress.
Kaikoura, New Zealand
19.4 Funguslike Protists TEKS 8B, 8C, 11C
KEY CONCEPT Funguslike protists decompose organic matter.
Fungus-like• Slime Molds• Water Molds
19.4 Funguslike Protists TEKS 8B, 8C, 11C
Slime molds and water molds are funguslike protists.• Slime molds have both funguslike and animallike traits.
– decomposers, like fungi – can move, like animals
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
composting- recycle organic matter
19.4 Funguslike Protists TEKS 8B, 8C, 11C
• Slime molds can be plasmodial or cellular.
– Plasmodial slime molds are giant cells with many nuclei.– Cellular slime molds contain independent cells.
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
19.4 Funguslike Protists TEKS 8B, 8C, 11C
• Water molds are freshwater, funguslike protists.– one type of water mold caused Great Potato Famine
of Ireland in the 1800’s – made of branching strands of cells – can be parasites of plants or fish