DOMAIN EUKARYA

KINGDOM PROTISTA II

Multicellular Protista (Red, Brown, Multicellular Protista (Red, Brown, & Green algae)& Green algae)

Major primary producers in aquatic systems Provide home for microorganisms and fishes The red and brown algae are primary multicellular and mostly

marine organisms Green algae contain many unicellular and mostly freshwater Cellulose is found in the cell wall of the three phyla among

others Green algae store carbs as starch in the chloroplasts Red algae store food as floridean & brown algae as laminarin,

outside the chloroplast Red algae lack flagella

Origins of chloroplast in AlgaeOrigins of chloroplast in Algae

Chloroplast of red algae resembles that of Cyanobacteria [Chl(a), carotenoid, phycobilins]

Chloroplasts of green algae, Euglenoids, & plants resemble that of Prochloron [Chl(a), (b), carotenoids]

Chloroplast of brown algae, Chrysophytes, & diatoms have the same origin!All have Chl a, c, & fucoxanthin.

1. 1. Brown Algae: Phylum Brown Algae: Phylum PhaeophytaPhaeophyta

Prefer cold agitated, well aerated water (temperate regions) Common on rocky shores (intertidal zones) They have a complex anatomy & morphology* Cell wall contain cellulose & alginic acid (not in other algae) Reserve food is Laminarin Range from small filamentous to large multicellular

organisms

BA

Examples of brown algae that grow in intertidal (shoreline) zone

Rockweed

BA

Kelp

Holdfast

Stipe

The giant kelps

- Are examples of brown algae that grow in deep clear waters (up to 30m)

- Brown & red algae provide food (SE Asia)

BA

Kelp, giant seaweed

Blade

Stipe

Holdfast

BA

Brown Algae: Brown Algae: EctocarpusEctocarpus

http://www.dipbot.unict.it/sistematica/Ectoc_pl.html

Plurilocular Sporangium

2. Green Algae (Phylum 2. Green Algae (Phylum Chlorophyta)Chlorophyta)

Include unicellular, colonial, and multicellular organisms They are resilient & survive many types of disturbances Mainly freshwater organisms Closely related to plants because:

Have chlorophylls a, b, & carotenoidsStore reserve food as starch in the chloroplastCell wall contains cellulose

Class ChlorophyceaeClass Chlorophyceae

The only living organisms in which cell division involves a phycoplast (Cleavage furrow)

Zygotic meiosis Mostly freshwater organisms Produce red, orange, & green snow Have flagellated and nonflagellated forms

GA

Chlorophyceae PhycoplastChlorophyceae Phycoplast

It insures that cleavage furrow passes between the daughter cells

Cell plateCleavage furrow

Motile Unicellular Motile Unicellular ChlorophyceaeChlorophyceae

Chlamydomonas: Unicellular Move by means of two flagella Asexual reproduction: haploid cells divide

by mitosis producing up to 16 cells Sexual reproduction

GA

ChlamedomonasChlamedomonas

Motile Unicellular Chlorophyceae GASexual reproduction induced by nitrogen starvation

Motile Colonial Chlorophyceae- A colony is an aggregate of independent cells

- Daughter colonies detach & form new colonies

- Cells’ flagella beat in a coordinate fashion

GA

Motile Colonial Chlorophyceae

http://www.botany.hawaii.edu/Bot480/Volvocales%20table%20of%20web%20links.htm

Nonmotile Unicellular Nonmotile Unicellular ChlorophyceaeChlorophyceae

Example: Chlorella: Lacks flagella, eyespots, and contractile vacuoles

Live in fresh, salt water, and in soil Reproduce only asexually (mitosis)

GA

algae.tcoalternativefuels.com/about-algae

Nonmotile Unicellular ChlorophyceaeNonmotile Unicellular Chlorophyceae

Chlorococcum oleofaciensChlorococcum oleofaciensFilled with asexual sporesFilled with asexual spores

Nonmotile colonial Nonmotile colonial Chlorophyceae:Chlorophyceae:

Example Hydrodictyon (water net) in ponds, lakes, and streams

GA

http://protist.i.hosei.ac.jp/PDB/Images/Chlorophyta/Hydrodictyon/

Filamentous Chlorophyceae:Filamentous Chlorophyceae:

Example Oedogonium Filamentous green algae are more complex Each cell has a specific function Cells are connected by plasmodesmata like

plants Sexual reproduction is oogamous, meiosis

is zygotic

GA

O. graciliusO. gracilius

http://vis-pc.plantbio.ohiou.edu/Hocking/photos/Oed.html

OOgonium

Class Ulvophyceae:Class Ulvophyceae:

Examples: Cladophora and Ulva* Marine organisms The only green algae with sporic meiosis Unlike other green algae, they rarely form

dormant zygospores

GA

Ulvophyceae:Ulvophyceae: Chladophora Chladophora

http://www.gettysburg.edu/~rcavalie/bda_i/091.html

http://www.uwinnipeg.ca/~simmons/cladoph.htm

UlvophyceaeUlvophyceae

Sea lettuce (Ulva)

The thallus is two cells thick and up to a meter long

GA

Class CharophyceaeClass Charophyceae

Unicellular, filamentous, and parenchymatous genera

Zygotic meiosis a. Spirogyra: (freshwater habitats)

GA

No flagellated stage in its life cycle Asexual reproduction by fragmentation Sexual reproduction via conjugation This forms a zygote which undergo meiosis

Conjugation

Union of two cells during which genetic material is exchanged

GA

Plants evolved from an extinct member of Plants evolved from an extinct member of Charophycease (Coleochaetales & Charales)!Charophycease (Coleochaetales & Charales)!

b. Chara (stoneworts) resembles ancestor of land plants!

Like plants they have apical growth (differentiated into nodal & internodal regions)

Produce antheridia & archegonia Sperms are flagellated Similar cytokinesis

http://www.aquaweed.com/chara.htm

GA

Cytokinesis in CharophyceaeCytokinesis in Charophyceae

C. In simple Charophytes: Cytokinesis occurs by furrowing

D. In advanced Charophytes: like plants (cell plate & plant-like phragmoplast. Spindles not persistent

Phragmoplast found in all green algae except chlorophyceae

3. Red Algae: Phylum 3. Red Algae: Phylum RhodophytaRhodophyta

Marine organisms, common to tropical & warm water Differ from other algae and plants in that:

Contain phycobilin pigments (red), Chloroplasts do not form grana stacks

Food reserves is floridean outside the chloroplastCell wall contain cellulose (galactans), calcium carbonate,

lack plasmodesmata Almost all red algae are multicellular Have no flagellated forms The source of agar (mucilage material in cell wall)

RA

Red Algae: Red Algae: Bonnemaisonia asparagoidesBonnemaisonia asparagoides

RA

http://www.horta.uac.pt/species/Algae/Bonnemaisonia_asparagoides/Bonnemaisonia_asparagoides.htm

Red Algae: Red Algae: Bonnemaisonia sppBonnemaisonia sppRA

http://www.horta.uac.pt/species/Algae/Bonnemaisonia_asparagoides/Bonnemaisonia_asparagoides.htm

Red Algae: Red Algae: Gelidium amansii

RA

http://www.botany.uwc.ac.za/presents/Seashore2/75.htm

Red Algae: Red Algae: Amphiroa carollineRA

http://www.globaldialog.com/~jrice/algae_page/bush_coralline.htm

Can be up to 1 meter long but generally smaller and more delicate than brown algae

RA Chondrus crispus