Type 1 Type 2

Type 3a

Type 3b

Picture Representations of The Three Types of

Protists

Kingdom ProtistaKingdom Protista

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Characteristics of ProtistsCharacteristics of Protists 60,000 + species60,000 + species EukaryotesEukaryotes Generally unicellularGenerally unicellular 10 10 μμm – 60 mm – 60 m Some have cell wallsSome have cell walls Some are motileSome are motile Some have pigmentsSome have pigments Various methods of feedingVarious methods of feeding

Most are aerobicMost are aerobic LackLack specialized features specialized features

of fungi, plants and of fungi, plants and animalsanimals

Do not develop complex Do not develop complex sex organssex organs

Do not form embryosDo not form embryos

Classifying ProtistaClassifying Protista They are divided into They are divided into threethree major groups major groups

based on their based on their type of nutritiontype of nutrition::1.1. ProtozoaProtozoa (animal-like)(animal-like)

heterotrophs that heterotrophs that ingest or absorbingest or absorb their food their food

2.2. AlgaeAlgae (plant-like) (plant-like) autotrophs that carry out autotrophs that carry out photosynthesisphotosynthesis

3.3. Slime MouldsSlime Moulds and and Water MouldsWater Moulds (fungi-like) (fungi-like) heterotrophsheterotrophs

1. Protozoa 1. Protozoa 2. Algae2. Algae 3. Slime Moulds3. Slime Moulds and and Water MouldsWater Moulds

1. Protozoa1. Protozoa They feed on other organisms, they may be They feed on other organisms, they may be

dead organisms. Some are scavengers, dead organisms. Some are scavengers, predators, or parasitic.predators, or parasitic.

They vary in shape and size. Most live as a They vary in shape and size. Most live as a single cell but some do form colonies.single cell but some do form colonies.

They are generally classified in They are generally classified in 4 phyla based 4 phyla based on their locomotionon their locomotion

1a) Flagellates1a) Flagellates Phylum ZoomastiginaPhylum Zoomastigina They have one or more flagellumThey have one or more flagellum They have a hard, protective covering over They have a hard, protective covering over

their outer membranetheir outer membrane

1b) Sarcodines1b) Sarcodines Phylum SarcodinaPhylum Sarcodina Also called amoebaAlso called amoeba They move and engulf They move and engulf

their prey by producing their prey by producing limb-like extensions of limb-like extensions of their cytoplasm, called their cytoplasm, called pseudopodiapseudopodia

One example is One example is foraminiferaforaminifera

1c) Ciliates1c) Ciliates Phylum CiliophoraPhylum Ciliophora They are covered in They are covered in

hundreds of cilia, hundreds of cilia, which allow them to which allow them to move and sweep food move and sweep food particles to them for particles to them for ingestioningestion

They are generally They are generally large and complexlarge and complex

1d) Sporozoans1d) Sporozoans Phylum SporozoaPhylum Sporozoa They are parasitesThey are parasites They form spores during their life cycleThey form spores during their life cycle

1. Protozoa1. Protozoa 4 types of locomotion4 types of locomotion

2. 2. AlgaeAlgae 3. Slime Moulds3. Slime Moulds and and Water MouldsWater Moulds

2. Algae2. Algae Simple, aquatic, chlorophyll-containing Simple, aquatic, chlorophyll-containing

organismsorganisms Range from single cells to giant seaweedsRange from single cells to giant seaweeds Greater than 2 billion years oldGreater than 2 billion years old They are classified into They are classified into 6 phylum based on 6 phylum based on

their different types of chlorophyll and other their different types of chlorophyll and other pigmentspigments. (3 are mainly unicellular; 3 mainly . (3 are mainly unicellular; 3 mainly multicellular). There are also differences in multicellular). There are also differences in their cell wall chemistry, and form of food their cell wall chemistry, and form of food reserve in their cells.reserve in their cells.

2a) Green Algae2a) Green Algae Phylum ChlorophytesPhylum Chlorophytes Same type of chlorophyll and colour as most Same type of chlorophyll and colour as most

land plantsland plants Cell walls contain celluloseCell walls contain cellulose Food reserves Food reserves →starch→starch Commonly found in fresh water and damp Commonly found in fresh water and damp

places on landplaces on land Many of the unicellular organisms have flagellaMany of the unicellular organisms have flagella

2b) Brown Algae2b) Brown Algae Phylum PhaeophtyesPhylum Phaeophtyes They are generally all the multicellular marine They are generally all the multicellular marine

organisms that we call seaweedsorganisms that we call seaweeds Cell walls → Cell walls →

cellulose and cellulose and alginic acidalginic acid

Typically found Typically found in cold waterin cold water

2c) Red Algae2c) Red Algae Phylum RhodophtyesPhylum Rhodophtyes Typically found in warmer seawaterTypically found in warmer seawater Able to grow at Able to grow at

greater depths greater depths than other algae than other algae because their because their pigments are pigments are able to move able to move through a greater through a greater distance in waterdistance in water

2d) Diatoms2d) Diatoms Phylum ChrysopyhtesPhylum Chrysopyhtes The most abundant The most abundant

unicellular algae in the oceansunicellular algae in the oceans They are a major food source They are a major food source

at the base of marine and at the base of marine and freshwater food websfreshwater food webs

Also a major source of Also a major source of atmospheric oxygenatmospheric oxygen

Cell walls Cell walls → rigid, silica→ rigid, silica

Diatoms: Sexual and Asexual Diatoms: Sexual and Asexual ReproductionReproduction

AsexualAsexual:: the organism splits into two, each the organism splits into two, each then grows a new half to fit inside the old one. then grows a new half to fit inside the old one. The rigid cell wall cannot grow once it has The rigid cell wall cannot grow once it has been formed. Therefore, each generation of been formed. Therefore, each generation of diatoms is smaller than the one beforediatoms is smaller than the one before

Sexual:: reduction in size continues until now. reduction in size continues until now. The diatoms produce a zygote that grows to The diatoms produce a zygote that grows to the original size before secreting a new cell the original size before secreting a new cell wall.wall. See Figure 12.32See Figure 12.32

2e) Dinoflagellates2e) Dinoflagellates Phylum PyrrophytesPhylum Pyrrophytes Unicellular, photosynthetic and mostly marineUnicellular, photosynthetic and mostly marine They have protective coats of stiff cellular They have protective coats of stiff cellular

platesplates They are distinguishable because they have They are distinguishable because they have

two flagella, one acts as a rudder and the other two flagella, one acts as a rudder and the other as a form of propulsion.as a form of propulsion.

They are also an important food sourceThey are also an important food source Reproduction is mainly cell division, they are Reproduction is mainly cell division, they are

capable of sexual reproductioncapable of sexual reproduction

2f) Euglenoids2f) Euglenoids Phylum EugenophytesPhylum Eugenophytes They also have two flagella but one is longer They also have two flagella but one is longer

than otherthan other Over ½ do not have chloroplasts and are Over ½ do not have chloroplasts and are

heterotrophsheterotrophs They could be autotrophic They could be autotrophic

or heterotrophicor heterotrophic

1. Protozoa1. Protozoa 4 types of locomotion4 types of locomotion

2. 2. AlgaeAlgae different types of chlorophyll different types of chlorophyll

and and other pigmentsother pigments

3. Slime Moulds3. Slime Moulds and and Water Water MouldsMoulds

3. Slime and Water Moulds3. Slime and Water Moulds Like fungi they have sporesLike fungi they have spores Like protozoa they glide from place to place Like protozoa they glide from place to place

and ingest foodand ingest food Like plants they have cellulose cell wallsLike plants they have cellulose cell walls There are 3 groups: 2 groups of slime moulds There are 3 groups: 2 groups of slime moulds

and 1 group of water mouldsand 1 group of water moulds

3a) Water Moulds3a) Water Moulds Phylum OomycotesPhylum Oomycotes Most live as saprotrophs on dead organic Most live as saprotrophs on dead organic

mattermatter Others live as parasites on fish, insects and Others live as parasites on fish, insects and

plantsplants They differ from other fungus-like protists by They differ from other fungus-like protists by

the nature of their spores and their sexual life the nature of their spores and their sexual life cyclecycle

3b) Plasmodial Slime Moulds3b) Plasmodial Slime Moulds Kingdom MyxomycotesKingdom Myxomycotes They are visible to the naked eye. They are They are visible to the naked eye. They are

blobs called plasmodium, which contain many blobs called plasmodium, which contain many nucleinuclei

They engulf their foodThey engulf their food They reproduce sexually where the They reproduce sexually where the

plasmodium develops spore-bearing structures plasmodium develops spore-bearing structures called sporangia. In dry periods spores develop called sporangia. In dry periods spores develop and when damp conditions return the spores and when damp conditions return the spores will germinate. The flagellae and the will germinate. The flagellae and the amoeboid cells fuse to make a zygote that will amoeboid cells fuse to make a zygote that will turn into a plasmodiumturn into a plasmodium

3c) Cellular Slim Moulds3c) Cellular Slim Moulds Phylum AcrasiomycotesPhylum Acrasiomycotes Exist as individual amoeboid cells with one Exist as individual amoeboid cells with one

nucleus each.nucleus each. Feed on tiny bacteria or yeast cells, when there Feed on tiny bacteria or yeast cells, when there

is no food a chemical is released which causes is no food a chemical is released which causes the cells to gather together in a the cells to gather together in a pseudoplasmodium.pseudoplasmodium.

The pseudoplasmodium goes through the same The pseudoplasmodium goes through the same reproduction as the plasmodial slime moulds.reproduction as the plasmodial slime moulds.

The two slime moulds are not suspected to be The two slime moulds are not suspected to be closely relatedclosely related

Life Cycle of a Slime MoldLife Cycle of a Slime Mold