In General • Usually unicellular

• Reproduction: Some asexual, some sexual, some both

• Kingdom for life that doesn’t fit in animals, plant or fungi kingdom

• Mostly aquatic life

• 3 main categories

• AKA: Protozoans

• Basic Features: – Aquatic, unicellular

– Heterotrophic: pathogens, parasites, predators

• Classified by how they move:

1) Pseudopods : move w/ pseudopodia (false- feet)

– Engulf by phagocytosis

– Ex: Amoebas

2) Flagellates: move w/ flagella

– Ex: Zooflagellates

3) Ciliates: move w/ cilia

– Ex: Paramecia

Animal-Like Protista

Amoeba (Pseudopod)

Flagellate Moving

Ciliate Moving

Animal-Like Protista & Disease

• Malaria

– Caused by: Plasmodium

• Vector: Mosquitoes

– Effects in humans: Fatigue, fever, vomiting, coma, death

• Sleeping sickness

– Caused by: Trypanosoma

• Vector: Tsetse flies

– Effects in humans: Coma & death

Plant-like Protista • AKA: Algae

• Most unicellular; No leaves, stems, roots

• Perform photosynthesis with chloroplasts

• Classified by their type of cell wall

1) Euglenoids: use flagella to swim

– Animal & plant-like

2) Dinoflagellates

– Most (~ 90%) plankton

– Basis of aquatic food chains

3) Diatoms

– Glasslike shells

– Provide ~ ½ the O2 on earth Red algae

Green algae

Brown algae

Euglena

Fungus-like Protista • Basic Features:

– Decomposers: Absorb and recycle nutrients

– Live in moist environments

• 2 major groups:

1) Slime Molds

– large (~1 meter) single celled mass of cytoplasm

– Fungus-like (absorbs food)

– Animal-like (can move)

2) Water molds: Can be parasitic

– Ex: Potato blight: caused Irish potato famine (1840’s)

Cool Slime Mold Video

Origins of Multicellularity

Protista live in 3 arrangements… • 1) Single-celled

– Live by themselves

• 2) Colonial

– Group of independent acting cells

– No specialized cells

• 3) Multicellular

– Cells specialized to be specific jobs

Importance: • Cells in colonies became efficient at

certain tasks.

• Cells & their offspring became specialized and dependent on each other.

= ANCESTORS OF MULTICELLULAR LIFE

Unicellular Euglena This is a colony of cells called Volvox

Multicellular Kelp

And lastly (if you couldn’t tell already)… Protists are difficult to classify

• Protista is one kingdom in the domain Eukarya.

– Some protists are not closely related.

– Molecular evidence supports reclassification.

– Protista classification will likely change.

REview • 1) Name the three categories of protista.

• 2) Which category of protista has members that are able to move?

• 3) Which category of protista has members that absorb nutrients?

• 4) Which category of protista has members that are heterotrophs?

• 5) Which category of protista has members that hunt?

• 6) How does a pseudopod, flagella, and cilia differ?

• 7) Name the 3 major categories of protozoa.

• 8) Name the 3 major categories of algae.

• 9) Name the 2 major categories of fungus-like protista.