Kingdom Protista Chapter 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 Pseudopod Nucleus

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 contractile vacuole 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 fish and 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

Dinoflagellates Nucleus 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- multicellular

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