Kingdom Protista

General Characteristics Any organism not classified as a—plant, animal, fungus, or bacteria (prokaryote). Protists are eukaryotic having a distinct nucleus and organelles. First Eukaryotes to evolve ~1.5 Billon years ago Most protists are unicellular (one-celled) but some are multicellular.

Protists are primarily classified according to how they obtain nutrition: Animal-like—heterotrophs (eat other organisms) b. Plant-like—autotrophs They contain chloroplasts and make their own food (photosynthesis). Fungus-like— Decomposers/Heterotrophs Didinium Paramecium eating Green like plants! Water mold

HOMEOSTASIS Structure Water Balance Pellicle – rigid microtubules, maintains shape Ectoplasm – outside cytoplasm Endoplasm – inside cytoplasm Water Balance Water enters protozoa through osmosis Contractile vacuole – maintains water and solute balance

REPRODUCTION Asexual reproduction Budding – pinching off of cell produces smaller daughter cell Binary fission – mitosis produces two identical offspring Multiple Fission– cell division that produces multiple cells

MOVEMENT Pseudopodia Pseudo – false Pod – foot Extension of cytoplasm Cilia Hairlike protein fibers Movement and attachment Flagella Thin protein whip Rotates or whips back and forth

Animal-like Protists (Protozoans) Method of Movement: Cilia—hair-like projections used for movement and feeding Cytoplasmic streaming—pseudopod (false foot) extends and cytoplasm streams into it. Video Video

I. Animal-like Protists Protozoan means “First Animal”. Cells contain a nucleus. Cells lack a cell wall. They are heterotrophs. Most can move on their own. Little Animals

4 Groups of Animal-like Protists Sarcodines (SAHR-koh-dighnz) Ciliates (SIHL-ee-ihts) Flagellates (FLAJ- ehl-ihts) Sporozoans (spohr-oh-ZOH-uhnz)

Sarcodines Have pseudopods (Greek:“false foot”) Extensions of the cell membrane and cytoplasm. Pseudopods are used for movement and to capture food. Many have shells. These shells form limestone, marble and chalk.

One type: Amoeba Most familiar Sarcodine. Pseudopods: Blob shaped. Contractile Vacuoles: controls amount of water inside Food Vacuole: where food is digested.

Amoeba: Nucleus Contractile Vacuole Pseudopod (False foot)

Split Personality Amoebas reproduce by dividing into two new cells (binary fission). Amoebas can respond to their environment. They are sensitive to light and some chemicals.

Ciliates Have cilia on the outside of their cells. Tiny hair-like projections used for movement, to gather food and as feelers.

Type: Paramecium Pellicle: tough outer wall. Slipper shaped Oral groove: like the mouth Gullet: holds food. Food Vacuole: digests food. Anal Pore: removes wastes 2 Contractile Vacuoles 2 Nuclei Reproduces by either binary fission or conjugation. Type: Paramecium

Paramecium: Contractile Vacuole Nucleus Cilia Oral Groove Collects and removes excess H2O (Maintains homeostasis) Nucleus Cilia Oral Groove Used to collect food Cell Membrane

Flagellates (Zooflagellates) Have a Flagellum: a long whip-like structure used for movement. Many live in animals Symbiosis a close relationship, at least one benefits. Mutualism: when both partners benefit.

Sporozoans All Sporozans are parasites. They feed on cells and body fluids. Form from Spores (tiny reproductive cells). Pass from one host to another. Pass from ticks, mosquitoes or other animals to humans.

Importance of Animal-like Protists: a. Harmful i. Disease-causing parasites spread by insect bites 1. Malaria—Plasmodium spread by mosquito 2. African Sleeping Sickness— Trypmosoma spread by Tsetse fly

Beneficial Recycles nutrients by breaking down dead matter Food source—for other organisms Mutualism—both organisms benefit Example: Trichonympha—makes it possible for termites to eat wood. Termites do not have the enzymes to digest wood.

a. Flagellum—whip-like structure used for movement 2. Euglena: Plant-like Protists 1. Method of Movement: a. Flagellum—whip-like structure used for movement 2. Euglena: Eyespot For photosynthesis (light) Flagella Nucleus Contractile Vacuole Chloroplasts

Plant-like Protists (Algae) Unicellular and Multicellular Colonies (groups of unicellular protists) Can move on their own Autotrophs: make their own food from simple materials using light energy (photosynthesis). 70% of the Earth’s oxygen is produced by Plant-like Protists! Pigments: chemicals that produce color

6 Groups of Plant like Protists Euglenoids (yoo-GLEE-noydz) Diatoms (DIGH-ah-tahmz) Dinoflagellates (digh-noh-FLAJ-eh-layts) Red Algae Green Algae Brown Algae

Unicellular Algae: Phytoplankton provides a source of nourishment for other organisms b. Protists recycle sewage and waste materials.

1. Euglenoids Green Unicellular Live in fresh water Autotrophs, but can be heterotrophs under certain conditions. Flagella Eyespot: sensitive to light. Chloroplasts Pellicle

2. Diatoms Unicellular 10,000 living species. Aquatic Glass like cell wall Diatomaceous earth: course powder that comes from dead diatoms (toothpaste, car polish & reflective paint.

3. Dinoflagellates Unicellular Cell walls are like plates of armor. Two flagella Spins when it moves. Colorful (pigments) Can glow in the dark. Causes Red Tide

Algal blooms are harmful when overgrown—deplete water of nutrients consequently killing fish. Algal blooms called Red Tides cause illness, paralysis, and death of fish and even humans.

Multicellular Algae: Examples--- Red Algae Green Algae Brown Algae

Red Algae Multicellular seaweeds Live in deep ocean waters Used for ice cream and hair conditioner Used as food in Asia

Green Algae Most are unicellular Some form colonies Few are multicellular Can live in fresh and salt water and on land in damp places. Very closely related to green plants.

Brown Algae Commonly called seaweed Can contain brown, green, yellow, orange and black pigments. Attach to rocks Have air bladders Giant Kelp can be 100 meters long! Used as food thickeners

Uses of Algae: Algae is a good food source for life in the oceans. Algae produces much of Earth’s oxygen through photosynthesis. Algae is used to make sushi, ice cream, salad dressing, plastics, paint, agar.

Fungus-like Protists Heterotrophs Have cell walls. Many have flagella and are able to move at some point in their lives. Three types: Slime Molds, Water & Downy Molds Reproduce with Spores (tiny cell that is able to grow into a new organism)

Water & Downy Molds Live in water or moist places. Tiny threads that look like fuzz. Attack food crops Caused the Irish Potato Famine.

Type: Slime Molds Reproduce by Fruiting Bodies: The Fruiting Bodies contain Spores. At first they look like amoeba, then later they look like mold. Live on moist shady places. Feed on bacteria and other microorganisms.

Fungus-like Protists: Examples— Slime molds Water molds

Importance of Fungus-like Protists: Beneficial— Recycles dead organic material. Results in rich, topsoil providing nutrients for plants.

Harmful— P. Infestans (water mold) caused Great Potato Famine in Ireland. This lead to the mass starvation of 1 million Irish people.