Kingdom ProtistaKingdom Protista

General CharacteristicsGeneral Characteristics

Protists are very Protists are very diversediverse and have few and have few traits in commontraits in common

Most are single-celled organisms, but Most are single-celled organisms, but some are many cells, and others live in some are many cells, and others live in coloniescolonies

Some produce own Some produce own foodfood, others eat other , others eat other organisms or decaying matterorganisms or decaying matter

Some can control own Some can control own movementmovement, others , others cannotcannot

Characteristics that protists Characteristics that protists DODO share: share:Eukaryotic (have a nucleus), but are less Eukaryotic (have a nucleus), but are less

complex than other eukaryotic organismscomplex than other eukaryotic organismsDo not have specialized Do not have specialized tissuestissues

Members of the kingdom Protista are Members of the kingdom Protista are related more by how they related more by how they differdiffer from from members of other kingdoms than by how members of other kingdoms than by how they are similar to other protiststhey are similar to other protists

Protists have many Protists have many different shapesdifferent shapes

Most scientists Most scientists agree that fungi, agree that fungi, plants, and animals plants, and animals evolved from early evolved from early protistsprotists

zooflagellates

ulva

Paramecium

Pretzel slim

e m

old

Protists and FoodProtists and Food

Protists can get food many ways:Protists can get food many ways:Can make own foodCan make own foodCan Can eateat other organisms other organismsCan eat parts or products of other organismsCan eat parts or products of other organismsCan eat Can eat remainsremains of other organisms of other organismsSome use more than one way to get foodSome use more than one way to get foodSome Some produceproduce food—they use food—they use chloroplastschloroplasts

to produce food through photosynthesisto produce food through photosynthesis

Finding FoodFinding FoodHeterotrophHeterotroph: organism that cannot : organism that cannot

makemake own food own foodSome are Some are decomposersdecomposers—they get —they get

energy by breaking down dead energy by breaking down dead organic matterorganic matter

Asexual ReproductionAsexual Reproduction

Most protists Most protists reproduce reproduce asexuallyasexually

Offspring come from Offspring come from just just oneone parent parent

Binary fissionBinary fission: a : a single-celled protist single-celled protist dividesdivides into two cells into two cells

Each new cell is a Each new cell is a single-celled protistsingle-celled protist

Sexual ReproductionSexual Reproduction

Requires two Requires two parentsparents Paramecium Paramecium

sometimes reproduce sometimes reproduce sexually by a process sexually by a process called called conjugationconjugation

Kinds of ProtistsKinds of Protists AlgaeAlgae

All algae have the All algae have the greengreen pigment pigment chlorophyll, which is chlorophyll, which is used to make food used to make food through photosynthesisthrough photosynthesis

Almost all algae live in Almost all algae live in waterwater

Free-floating, single-Free-floating, single-celled algae are called celled algae are called phytoplanktonphytoplankton, which , which produce much of the produce much of the world’s world’s oxygenoxygen

AmoebasAmoebas Soft, jellylike Soft, jellylike

protozoansprotozoans Found in fresh and salt Found in fresh and salt

water, soil, and in water, soil, and in parasitesparasites

Move with Move with pseudopodia, which pseudopodia, which means “means “false feetfalse feet””

CiliatesCiliates Have hundreds of Have hundreds of ciliacilia——

tiny, hairlike structurestiny, hairlike structures Cilia Cilia movemove the protist the protist

forward by beating back forward by beating back and forth—sometimes up and forth—sometimes up to 60 times a second!to 60 times a second!

Cilia are also used for Cilia are also used for feedingfeeding—they move the —they move the food towards the protist’s food towards the protist’s food passagewayfood passageway

Best known of ciliates is Best known of ciliates is the Parameciumthe Paramecium

Spore-Forming ProtistsSpore-Forming Protists Many spore-forming Many spore-forming

protists are parasitesprotists are parasites They They absorbabsorb nutrients from nutrients from

their hoststheir hosts No cilia or flagella, cannot No cilia or flagella, cannot

movemove on their own on their own Have complicated life Have complicated life

cycles that usually cycles that usually includes two or more hostsincludes two or more hosts

Example: protist that Example: protist that causes malaria uses both causes malaria uses both mosquitoes and humans mosquitoes and humans as hostsas hosts

Slime MoldsSlime Molds Heterotrophic and can Heterotrophic and can

only move during certain only move during certain periods of life cycleperiods of life cycle

Look like Look like thinthin, colorful , colorful globs of slimeglobs of slime

Use pseudopodia to Use pseudopodia to movemove and eat fungi and and eat fungi and yeastyeast

When environmental When environmental conditions are stressful, conditions are stressful, slime molds grow slime molds grow stalksstalks with knobs, which contain with knobs, which contain sporesspores

Red AlgaeRed Algae Most of world’s Most of world’s

seaweedseaweed is red algae is red algae Most live in tropical Most live in tropical

oceansoceans Usually less than 1 m Usually less than 1 m

in lengthin length Contain chlorophyll, Contain chlorophyll,

but have but have redred pigmentpigment Red pigment allows Red pigment allows

them to absorb them to absorb light light that filters deep into that filters deep into oceanocean

Brown algaeBrown algaeMost seaweed in Most seaweed in coolcool

climates are brown climates are brown algaealgae

Attach to rocks or form Attach to rocks or form large floating beds in large floating beds in ocean watersocean waters

Have chlorophyll and Have chlorophyll and yellow-brown pigmentyellow-brown pigment

Many are very Many are very largelarge—up —up to 60 metersto 60 meters

Green algaeGreen algae Most diverse of protist Most diverse of protist producersproducers Green because Green because chlorophyllchlorophyll is main pigment is main pigment Most live in water or moist soilMost live in water or moist soil Others live in melting snow, on tree trunks, and Others live in melting snow, on tree trunks, and

inside other organismsinside other organisms

DiatomsDiatoms Single-celledSingle-celled Found in salt and fresh waterFound in salt and fresh water Get energy from Get energy from photosynthesisphotosynthesis Make up a large percentage of phytoplanktonMake up a large percentage of phytoplankton Cell walls contain a glasslike substance called Cell walls contain a glasslike substance called silicasilica