• Kingdom Protista includes more than 50,000 kinds of organisms.

• They consist of single-celled or simple multicellular eukaryotic organisms that generally do not fit in any other kingdom.

• Most, but not all are microscopic.

• First evolved about 2 billion years ago through the endosymbiosis of small and larger prokaryotes.

• Overall characteristics vary widely:• Some are unicellular. Ex: Amoeba• Some form colonies. Ex: Volvox• Some are multicellular. Ex: Brown Algae•Many are autotrophs; making food through photosynthesis• Some are heterotrophs; either eating other protists or by decomposing and absorbing nutrients as fungi do.• Variety of ways to move: flagella, cilia, or pseudopods

• Most reproduce asexually by binary fission or multiple fission• Binary fission: one cell divides into two identical cells• Multiple fission: one cell divides into more than two

cells

• Some reproduce sexually by conjugation• Two cells join and exchange genetic material• Then each divides to produce four new offspring.

• Three main groups of protists are generally recognized:

Animal-like

Plant-like

Fungus-like

• Often called Protozoans•Unicellular (one-celled)•Cannot make food: eat bacteria, algae, and other protozoans•Four phyla based on movement: Protozoa, Ciliophora, Sarcomastigophora, and Apicomplexa

• Move and feed by using finger-like projections called pseudopods

• Most live in freshwater.

• All change shape as they move.

• Example: Amoeba Amoeba feeding on a bacterial cell.

• Move by tiny hair-like structures called cilia.

• Most live in freshwater.• Slipper-shaped.

Surrounded by a membrane-like structure called a pellicle.

• All have two nuclei: macronucleus (controls most cell activities) and micronucleus (controls reproduction)

• Ex: Paramecium

Contractile vacuole controlswater movement in and out.Feed through oral groove

• Move by using a whip-like tail called a flagella.

• Some have one flagella, others have many.

• Live in fresh or salt water or as disease-causing parasites in animals.

• Example: Trypanosome flagellate causes African Sleeping Sickness. It is transmitted by the bite of the tsetse fly.

Trypanosome flagellate

Tsetse fly

• Also known as sporozoans.• Animal-like protists that live as

parasites.• Can not move on their own.• Most feed on the blood of human

or animal hosts.• Malaria is caused by a sporozoan

called Plasmodium. It is transmitted by the bite of the Anopheles mosquito. The plasmodium produce poisons that cause fever and chills.

Anopheles mosquito

Sporozoans

• Also known as algae.•Can be single-celled, many-celled or live in colonies.•All contain chlorophyll and can make food.•Some contain other colored pigments as well.•Classified into seven phyla based on the pigments they contain and the number of cells

• Important part of the microscopic plants and animals found floating near the surface of water known as plankton. • Plant-like plankton that makes its

own food is called phytoplankton. • It is responsible for producing about 90% of the earth’s oxygen as well as being an important part of the food chain.

• Green Algae• Ancestors of green plants.• Contain chlorophyll a and b and store food as starch.•Most species are freshwater and can be single-celled, live in colonies, or in filamentous, multicellular forms• Salt-water species are many celled.

Volvox

Ulva

Spirogyra

• Brown Algae•Contains chlorophylls a and c•Saltwater algae known as seaweed or kelp.•Common along rock coast lines in cold water.•Grow very large (100m)•Many have small, light-colored structures called air bladders to keep them floating near the surface.

• Red Algae• Contain chlorophyll a and phycobilins that allow them to absorb wavelengths of light from deep water.• Also called seaweed.• Found in deep ocean water.• Used to make agar, and in pudding, ice cream, cheese, salad dressing and marshmallows

• Diatoms• Yellow or brown in color. Come in many shapes and patterns.• Covered by shells that are made of a glass-like substance known as silica. These shells are used in toothpaste, silver polish, detergents, insulation and road paint.

• Fire algae•Many are red in color. Found in salt water.•Most have two flagella and spin as they move• Responsible for red-tides (Ocean turns red because of a population explosion of fire algae. The algae produce poisons that can kill fish and people).

• Golden Algae•Most live in freshwater• Form highly resistant cysts to survive in frozen or dried up lake beds• Store energy as oil• Probably play a role in formation of petroleum deposits

• Euglenoids• Have both plant and animal like characteristics.• Can make food when light is present. Can eat food when it is not. • Have an eyespot that responds to light (swims toward it).•Move by using a flagella

• Fungus-like protists —also known as slime molds and water molds.• They have features of both protists and fungi.• Four phyla:

Phylum Myxomycota:Plasmodial Slime Mold

Phylum Oomycota:Water mold

Phylum Dictyostelida: Cellular Slime Mold

Phylum Chytridiomycota:Water mold

• Slime molds —two stage life cycle: • Reproductive stage: resembles a fungus• Feeding stage: resembles an amoeba (protist)• During the feeding stage, slime molds appear in one of

two forms: plasmodial slime molds (consisting of a large mass of cytoplasm with many nuclei); and cellular slime molds (consisting of individual amoebalike cells).

Plasmodial slime mold Cellular slime mold

• Most are parasitic and grow as long filaments on the host, eventually harming them.

• Kingdom Fungi — consists of many-celled organisms that can not make food and can not move around.• Do not have chlorophyll.• Most get food by decomposing and absorbing dead

organic matter (saprophytes).• Some get food from living host organisms (parasites).• Fungi do not have roots, leaves or tissue layers.• Store energy in the form of glycogen.

• The body of a fungus is made of a mass of thread-like tubes known as hyphae.• Hyphae usually grow

underground and may join to form above ground reproductive structures like mushroom caps.• Cell walls made of chitin.• Grow best in warm, moist

places.• Reproduce by forming spores.

• Zygote Fungi: spores are produced in round spore cases called sporangia.• Example: Bread mold

• Club Fungi: spores are produced in a club-shaped structure called a basidium (pl. basidia)• Examples: mushrooms and rusts

• Sac Fungi: spores are produced in a sac-like structure called an ascus (pl. asci)• Examples: yeasts,

molds, morels and truffles

• Imperfect Fungi: reproductive stage has never been observed.• Examples: ringworm fungus, athletes foot fungus

and Penicillium (used to make Penicillin).

Ringworm infection Athletes foot infection

• A micorrhiza is a symbiotic structure formed by a fungus and plant roots.

• More than 80% of vascular plants contain such fungi on their roots.• The fungus absorbs and concentrates nitrogen, phosphate and other ions for the plant’s use• The plant supplies the fungus with sugar from photosynthesis

The micorrhizae appear asnodules on the plant’s roots

• A lichen is actually two organisms living together: a fungus and an algae (or cyanobacteria)

• Both benefit• Algae makes food for fungus.• Fungus improves living conditions for algae by secreting acids that begin to break rock into soil.• Live on rocks, soil, branches or tree trunks.• Considered a pioneer species