Kingdom Protista

What’s a Protist?

• Protist, not Protest

• Protists are:– Eukaryotes (cells have nucleus & organelles)– Mainly single-celled, but have multicellular also– Not a fungus, a plant, or an animal

• 3 Types:– Animal-Like, Plant-Like, & Fungus-Like Protists

Animal-Like Protists

• Known as PROTOZOANS (first animal)

• Heterotrophic– Get energy from other organisms

• 4 Types: distinguished by their movement– Zooflagellates– Sarcodines– Ciliates– Sporozoans

Zooflagellates• Move by using FLAGELLA

• Have one or two flagella

• Absorb food through cell membrane from dead organisms

• Live in streams or lakes

• Reproduce Asexually by mitosis

or Sexually by meiosis

Sarcodines

• Move with PSEUDOPODS – These are cytoplasmic extensions

• Also use PSEUDOPODS for feeding– They surround food with membrane making a

food vacoule

• Examples:– Amoebas, Foraminiferans,

& Heliozoans

Ciliates• Use CILIA for feeding and movement

– Instead of having only 1 or 2, they have many cilias

• Use cilia to move food into gullet and make food vacoule

• Reproduce their mitosis

• Also go through conjugation to pass genes (just like some bacteria)

• Example: Paramecium

Sporozoans• Unique because they don’t move freely

• PARASITIC – live in host

• Reproduce through SPOROZOITES– Sporozoites attach to a host cell and

penetrate it to live in it

Protozoans & Diseases• Malaria

– Caused by sporozoan Plasmodium– Passed on by mosquitoes

• African Sleeping Sickness– Caused by zooflagellate Trypanosoma– Transmitted by bite of the tsetse fly– Effects nervous system; fall into fatal sleep

• Amebic Dysentary– Caused by amoeba Entamoeba

Part 2

Plant-Like Protists – Unicellular

• Unicellular ALGAE

• Why plant-like?– Because contain pigments & photosynthetic– Contain chlorophyll & accessory pigments

• 4 Types:1) Euglenophytes 3) Diatoms

2) Chrysophytes 4) Dinoflagellates

Euglenophytes

• Have 2 flagella

• Have chloroplast & chlorophyll– Unlike plants = no cell wall– For protection instead have Pellicle

• Have EYESPOT = cluster of red pigments to help find sunlight

• Reproduce asexually by Binary Fission

Chrysophytes

• Name means “Golden Plants”

• Yellow-Green Algae

• Cell wall contains pectin & cellulose

• Store food as oil, not starch (like plants)

• Reproduce asexually & sexually

Diatoms

• Most abundant organism

• Cell walls made of silicon (Si) – Silicon is the main

component of glass

• Look like two petri-dishes on each other

• When they die, make Diatomaceous Earth

Dinoflagellates

• ½ are Photosynthetic & ½ are Heterotrophic

• Have 2 flagella that wrap around body

• Cell wall made of Cellulose (like plants)

• Reproduce asexually (Binary Fission)

Plant-Like Protists – Multicellular

• Multicellular ALGAE

1) Green Algae

2) Red Algae

3) Brown Algae

• Biggest Difference is their Pigments

Green Algae• Extremely similar to plants:

– Have chlorophyll a and b– Cell walls of cellulose– Stores food as starch

• Can be unicellular, colonial, & multicellular

Brown Algae• Contains chlorophyll

a and c

• Also contains fucoxanthin (brown pigment)

• Largest known algae, Giant Kelp

General Structure:

Red Algae

• Have chlorophyll a & phycobilins (red pigment)

• Good at making energy, so grow in deep water

• Important to coral reefs

Reproduction in Algae

• Many life cycles have two generations:– Haploid (n) = Spores & Gametes

– Diploid (2n) = Sporophyte & Zygote

Human Uses of Algae

• Major Food Source

1) Sushi • Dried & used as a wrap (Porphira – red algae)• Also used for salad (Green algae)

2) Ice cream, Cheese, Syrups, Puddings• Algin – Brown Algae• Carrageenan – Red Algae

• Industrial Uses– Algin used for paint, rubber, cosmetics– Pigments also used for medicine & pharmaceuticals

Part 3

Fungus-Like Protists• Like fungus, these are Heterotrophs

– Absorb nutrients from dead organisms

• Key role = recycle organic material

• Unlike true fungus:– Have centrioles– Don’t have chitin cell walls

• 2 Types:1) Slime Molds & 2) Water Molds

Slime Molds

• Two Groups:– Cellular Slime Molds & Acellular Slime Molds

(seperated by cell membrane) (cells fuse to form 1 with many nuclei)

• Cellular Slime Molds– Free Living, but release chemicals to attract individuals– Form colonies– Reproduce by Fruiting Body that releases spores

• Acellular Slime Molds– Single cells fuse together to form PLASMODIA– Fruiting bodies spring up and release spores with flagella

Water Molds

• Thrive on dead or decaying organisms

• Some live on land as plant parasites

• Produce HYPHAE:– Many cells together– Cell walls made of cellulose– Produce spores that are motile

• Reproduce both asexually & sexually– Antheridium = produces male nuclei– Oogonium = produces female nuclei