Outline: Kingdom Protista Kingdom: Protista ... · PDF fileKingdom: Protista • Endosymbiosis • Classifying Protists ... General Biology of Protists Reproduction Nutrition ... Sexual

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Chapter 28

Kingdom: Protista• Endosymbiosis• Classifying Protists• General Biology of Protists• Six Lineages & 15 Phyla

– Euglenozoa– Alveolata– Stramenopila– Rhodophyta– Chlorophyta– Choanoflagellida

Outline: Kingdom Protista

…and…AmoebasRadiolariansForaminiferansSlime Molds

General Biology of Protists

Reproduction

Nutrition

Dormancy

Locomotion

Cell surface

Cell Organization Eukaryotic, Unicells, Colonials and Multicellular

Extracellular Material (“wall”)…chitin, cellulose, silica

Plasma membrane – always

Some move….pseudopodia, flagella, cilia

Some don’t move

Cyst formation …..Cell Metabolism shuts down….. Protects Cell from adverse conditions

Heterotrophs….phagotrophs & osmotrophs

Photoautotrophs

Sexual ….. Meiosis ….. Schizogony – many nuclear divisions… several cells ….. Budding (unequal division) ….. Binary fission (equal halves)

Asexual….. mitosis and cytokinesis

The first eukaryote?Pelomyxa palustris –

amoeba-like ancient protist

1. Internal membranes like eukaryotes2. Nuclei 1- many3. Nuclear mitosis …Nucleus pinches in two4. NO mitochondria… but

Symbiotic bacteria live in cytoplasm5. Resembles Archaebacteria

fiEukaryotes evolved from Archaebacteria ??

Fairmead pond in Epping Forest

Ancestral eukaryotic cell & internal membrane system

Eukaryotic cell withmitochondrion

Mitochondrion

Fig. 28.3(TE Art)

Endosymbiosis

PhotosyntheticBacterium

Aerobicbacterium

Eukaryotic cell with chloroplasts

Chloroplast

Photosynthetic organisms

Overview of Protist Classification

Bacteria

Animals

FungiPlants

Archaea

bacteria

Protista

Eukaryotic Cell

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Fig. 28.4(TE Art)

Euglenozo

a

EuglenoidsKinetoplastids

Alveolat

a

DinoflagellatesApicomplexes

Ciliates

Stramen

opila

Brown algaeDiatoms

Oomycetes

Rhodophyta

Red Algae

Choanofla

gellida

ChoanoflagellatesAmoebasForams

Slime Molds

Six Protist Monophyletic (?) Lineages

Chlorophyta

Green Algae


Protist ClassificationLineage: Euglenozoa

Lineage Euglenozoa: Euglenoids

– 40 genera, single-celled, mostly freshwater– 1/3 photoautotrophic, 2/3 heterotrophic– Motile – Move by flagella

Euglenozoa: Euglenoids

EM views of pellicle

Euglenozoa: Kinetoplastids

Genus: Trypanosoma

Kinetoplast in mitochondrion

Kinetoplastid(mitochondrion)

Kinetoplastid CharacteristicsKinetoplast = One mitochondrion per cell

–Mitochondrion extends full length of cell–Mitochondrial genome = kinetoplast–Kinetoplast DNA

Maxicircles 50 per cell15 & 80 Kbp

Minicircles 10,000 per cell0.9 & 2.5 Kbp

Function:Rapid glycolysisDNA editing by RNA

Kinetoplastminicircles

Kinetoplast

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Diseases caused by Trypanosomes1. Sleeping sickness, leishmaniasis & Chagas’ disease2. > 4 million affected annually3. Control difficult:

2000 variable cell membrane glycoprotein genes

Macrophage filledwith leishmania trypanosomes

Diseases caused by Trypanosomes – Leishmaniasis

1. tropical/subtropical: 88 countries2. 2 million infections

cutaneousvisceral (internal organs)

3. Vector sand fly

Sand fly vector

Diseases caused by Trypanosomes – Chagas’ Disease1. Disease agent = Trypanosoma cruzi2. Vector Kissing bug & blood transfusions3. 30 million people infected (Central & South America)4. Symtoms: acute: swollen eye, fever, fatigue, organ

involvement, brain swellingchronic: 10-20 yrs later

weakened cardiac musclemegacolon

Kissing bug Early infection Infected muscle16

Protist Classification

DinoflagellatesApicomplexansCiliates

Alveolata: DinoflagellatesAlveolus = flattened vesicle below

plasma membraneSingle-celled, 2 flagella in grooves

2100 species mostly marine

Cell Wall – sometimes presentCellulose plates, maybe some silica

Nutrition – about 50% autotrophicChloroplasts with 3 membranesChlorophyll a, c Carotenoids: fucoxanthin

ChromosomesNo histones with DNAAttached to Nuclear Membrane Condensed throughout interphase

Importance (autotrophs)40% global productivityZooxanthellaeRed tidesBioluminescence

alveolus

Alveolata: Dinoflagellates

jellyfish

Anemone

Coral

Zooxanthellaesymbiotic dinoflagellates

Ceratium – A planktonicdinoflagellate

Spotted jellyfish with zooxanthellae Bleached coral lacking zooxanthellae

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Alveolata: DinoflagellatesDinoflagellate blooms = red tides

Pfeisteria bloomNoctiluca bloom saxotoxin

Na+ channel blocker

Noctiluca cells

Alveolata: DinoflagellatesBioluminescence in Pyrodinium bahamense Protist Classification

DinoflagellatesApicomplexans

Ciliates

Group: AlveolataApicomplexesExample: Plasmodium

• Api = apical • complexa = complex• Apical end of cell complex

mass of organelles…– Microtubules– Fibrils– Vacuoles

• All parasites of animals• Unicells• Nonmotile

Group: Alveolata – ApicomplexesPlasmodium & Malaria

Animation of Plasmodium Life Cycle

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Merozoitesreleased from red blood cell

Trophozoitering stage

Gametocyte

Group: Alveolata ApicomplexesPlasmodium & Malaria

Occurrence: 500 million people infected globally1 billion people at risk2 million deaths annually

CLINICAL PICTURE:• Cyclical chills & Fever• Incubation period: days to years• Headache, enlarged spleen• Adult respiratory distress syndrome• Severe hemolysis• Renal failure• Incubation: Days to Years

Group: Alveolata ApicomplexesPlasmodium Malaria


DinoflagellatesApicomplexans

Ciliates

• 8000 species• Heterotrophic…but…• Unicellular • Many Cilia • Pellicle = flexible covering• Gullet = cytostome

Group: AlveolataCiliatesExample:Paramecium

P. bursaria with endosymbiotic alga

•Vacuoles – Two typesFoodContractile

•Nuclei – twoMicronucleusMacronucleus

Group: Alveolata CiliatesExample:Paramecium

Video of contractile vacuole


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Trichocysts


Fig. 35.22a

Asexual reproductionmitosis & cytokinesis

Sexual reproduction1. different mating types fuse2. meiosis of micronuclei3. 3 of 4 degenerate4. remaining micronuclei divide

mitotically5. micronuclei exchange6. fuse to form diploid micronuclei

Group: Alveolata CiliatesExample: Paramecium Reproduction

Summary of Protists Examined Thus Far

• Group: Euglenozoa• Euglenoids Euglena• Kinetoplastids Trypanosoma

• Group: Alveolata• Dinoflagellates photosynthetic plankton• Apicomplexes Plasmodium• Ciliates Paramecium


Brown AlgaeDiatoms

Water molds

Group Stramenopila –Characteristics1. Flagella: Lateral & heterokont

1. Tinsel type has mastigonemes2. Whiplash – no hairs

2. Cell wall: cellulose

3. Nutrition: Autotrophs & Heterotrophs1. Autotroph chloroplasts

1. chlorophyll a and c2. carotenoid pigments = fucoxanthin

4. Three groups1.Brown algae2.Diatoms3.Oomycetes = water molds

Group Stramenopila – Brown Algae

Video Link Kelp

Live video feedBrown algae epiphytes

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Group Stramenopila

Brown Algae KelpGroup Stramenopila – Brown Algae Macrocystis

Stramenopila – Brown Algae Intertidal habitat StramenopilaBrown AlgaeEcological Importance

Sargassum

Stramenopila Brown Algae Sargasso sea – a Kelp-dominated ecosystem Brown algae

Economic Importance

Additives Stabilizers

Binding agents

Food Kombu

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Brown AlgaeDiatoms

Oomycetes

Single-celled, 11,000 species50% marine

Cell Wall: SilicaAutotrophicPigments

Chlorophyll a, c CarotenoidsFucoxanthin

Food reserveChrysolaminarinOils

Importance40% global productivityAbrasives & filter aids

Group Stramenopila Diatoms

Group Stramenopila DiatomsSilica shells & SymmetryCentric

Pennate

SeaWiFS Satellite Imagery Chlorophyll & Phytoplankton

Diatom Commercial Applications

Dynamite

Filter


Brown AlgaeDiatoms

Oomycetes = Water Molds

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Group Stramenopila: OomycetesWater molds & downy mildews

Heterotrophic ProtistsAquatic: Fresh or salt waterTerrestrial: SoilParasitic or saprotrophicHypha & HyphaeCellulosic walls

Vegetative hyphae

Sexual reproduction

Group Stramenopila OomycetesReproduction in Saprolegnia – a water mold

Asexual reproduction

Group Stramenopila OomycetesSaprolegnia (water mold)

Plasmopara (downy mildew)

Group Stramenopila Oomycetes

Phytophthora

Irish Potato Famine & Late Blight1845-49 1 million deathsLate 1900’s 1.1 million emigrated

Eugl

enoz

oa

Stra

men

opila

Alve

olat

a

PlantsChloro

phyta

Rhodo

phyta

Choan

oflag

ellida

AnimalsFungi




Ciliates

Brown algaeDiatoms

Oomycetes

Red algae Green algae

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Size: Microscopic to macrophytes

Distribution: 98% marine – 7000sp

Locomotion: None

Pigments: chlorophyll aPhycocyanin & phycoerythrin

Storage material:Floridean Starch and mannitol

Cell Wall: Cellulose & biocolloids

Importance: Producer organismsMarine Environments

RhodophytaRed Algae

LithothamnionPorphyra (nori)Antithamnion

Halosaccion

RhodophytaRed algaeMorphology

Porphyridium

Palmaria palmata (dulse)

RhodophytaEcological ImportanceHimantothallus in Antarctica

Lophophora – encrusting red alga Mastophora – lamellate red alga

Phylum: Rhodophyta Economic Importance

Eugl

enoz

oa

Stra

men

opila

Alve

olat

a

PlantsChloro

phyta

Rhodo

phyta

Choan

oflag

ellida

AnimalsFungi




Ciliates

Brown algaeDiatoms

Oomycetes

Red algae Green algae

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Size and habit of growth7000 species, mostly fresh waterEnormous diversity

Pigments: Chlorophyll a, bCarotenoids

Storage materialStarch

Cell WallCellulose & pectins

Locomotion: Many have flagellated stage

ChlorophytaGreen Algae

Chlorophyta Morphology

Unicells Filamentous Colonial

Branched, filamentous Membranous

Complex

Chlorophyta Freshwater Habitat

Autotrophic Protists – Green algae

Chlorophyta Snowfield Habitat

Chlamydomonas

Chlorophyta: Importance1.Producer organisms

2.Food? Chlorella …a place in space

3. Sewage treatment Scenedesmus…accumulates nitrates & phosphates

4. Fuel?

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Eugl

enoz

oa

Stra

men

opila

Alve

olat

a

PlantsChloro

phyta

Rhodo

phyta

Choan

oflag

ellida

AnimalsFungi




Ciliates

Brown algaeDiatoms

Oomycetes

Red algae Green algae Choanoflagellates

Choanoflagellida - Choanoflagellates

• Heterotrophic protists• Colonial forms• Single emergent flagellum• Collar – strains bacteria• Closely related to sponges• … and animals

Other Protists

• Amoebas, Radiolarians & Foraminiferans• Slime Molds

• No permanent locomotor apparatus• Amorphous• Move by pseudopodia• No cell walls• No meiosis

Entamoeba histolytica

Protists - Amoebas

• Marine planktonic amoebas • Test - glassy silica exoskeletons• Planktonic – mostly warm, equatorial waters

Actinoma

Amoeboid Protists - Radiolarians

Actinosphaerium

Amoeboid Protists - Radiolarians

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Amoeboid Protists - RadiolariansAxopodia Needle-like podia Extrude out of pores •Heterotrophic Marine protists

•Planktonic or Bottom Dwellers

•Shell = test•Organic material + CaCO3•Multichambered

•Podia emerge from test•Swimming•Gathering•Feeding

•Great Fossil Record

Protists – Foraminiferans

K/T boundary

RadiolariansCretaceous extinction

Pre-impact Cretaceous (fossil) forams. 2 cm below the K/T layer

Post-impact tertiary forams. 1cm above K/T layer

Fossil forams and mass extinction

White Cliffs of Dover

Fossil forams

Recent Forams

ForaminiferaForam Sand Beach

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Protists: Slime MoldsExample: Physarum

•500 species

•Heterotrophic Protists

•plasmodium

•Multinucleate

•Amoeboid like streaming of cytoplasm

Slime mold sporangia

Fig. 35.27

Eugl

enoz

oa

Stra

men

opila

Alve

olat

a

PlantsChlor

ophy

ta

Rhodo

phyta

Choan

oflag

ellida

AnimalsFungi


AmoebasRadiolariansForaminiferansSlime Molds

?

Ancestral Eukaryote

END

Multicellular Algae

ENDProtists

Documents

Outline: Kingdom Protista Kingdom: Protista ... · PDF fileKingdom: Protista • Endosymbiosis • Classifying Protists ... General Biology of Protists Reproduction Nutrition ... Sexual