Download - Presentation Mar 410 Seaweed
SEAWEEDSEAWEED(Marine Algae =(Marine Algae =
multicellularalgae)multicellularalgae)
Types of AlgaeTypes of Algae
Chlorophyta = Chlorophyta = GreenGreenPhaeophyta = Phaeophyta = BrownBrownRhodophyta = Rhodophyta = RedRed
REPRODUCTION OF REPRODUCTION OF SEAWEEDSEAWEED
FragmentationFragmentation-asexual reproduction in -asexual reproduction in which the thallus breaks up into pieces, which the thallus breaks up into pieces, which grow into new algae.which grow into new algae.
Through spore formationThrough spore formation:-:- haploid spores ae formed are within an haploid spores ae formed are within an
area of the thallus(sporangium) through area of the thallus(sporangium) through meoisismeoisis
Sporophyte- stage of the life cycle that Sporophyte- stage of the life cycle that produce spores which is diploidproduce spores which is diploid
Cont..Cont..
OedogoniumOedogonium is a multicellular, is a multicellular, filamentous filamentous green algaegreen algae with specialized with specialized cells called gametangia that form cells called gametangia that form gametesgametes
The male gametangia or antheridium The male gametangia or antheridium makes sperm, & the female gametangia makes sperm, & the female gametangia or oogonium makes eggsor oogonium makes eggs
Sperm are released into the water & Sperm are released into the water & swim to the egg to fertilize themswim to the egg to fertilize them
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The fertilized egg or zygote is released The fertilized egg or zygote is released from the oogonium & forms thick-walled from the oogonium & forms thick-walled zoospores Zoosporeszoospores Zoospores
undergo meiosis so one cell attaches to undergo meiosis so one cell attaches to the bottom & develops a holdfast while the bottom & develops a holdfast while the other zoospores divide & form a the other zoospores divide & form a filamentfilament
OedogoniumOedogonium Life Cycle Life Cycle
Conjugation Tube between Conjugation Tube between SpirogyraSpirogyra
SpirogyraSpirogyra, another filamentous green algae, , another filamentous green algae, reproduces by conjugationreproduces by conjugation
Two filaments align side by side, their Two filaments align side by side, their adjacent cell walls dissolve, & a conjugation adjacent cell walls dissolve, & a conjugation tube forms between themtube forms between them
Fertilization occurs when a + gamete cell Fertilization occurs when a + gamete cell moves through the tube & fuses to the - moves through the tube & fuses to the - gamete cell gamete cell
Zygote forms a thick walled spore Zygote forms a thick walled spore (sporangium) that breaks away from the (sporangium) that breaks away from the parent & forms a new filamentparent & forms a new filament
Conjugation Tube between Conjugation Tube between SpirogyraSpirogyra
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Sexual reproductionSexual reproduction Gametes fuses to form a diploid Gametes fuses to form a diploid
zygotezygote Gametophyte- stage of the life cycle Gametophyte- stage of the life cycle
that produce gametes that produce gametes Gametangia- structure where Gametangia- structure where
gametes are typically produced.gametes are typically produced.
Alternation of generationAlternation of generation The adult seaweed plant cells are The adult seaweed plant cells are
diploiddiploid,contain two sets of ,contain two sets of chromosomes.chromosomes.
Diploid plants, Diploid plants, sporophytessporophytes, produce , produce and release haploid spores ,by and release haploid spores ,by meiosis(n)meiosis(n)
the haploid spores settle and grow the haploid spores settle and grow into into gametophytesgametophytes
• The gametophytes produce sperm or The gametophytes produce sperm or eggs. eggs.
• When the sperm and eggare When the sperm and eggare fused fused togethertogether(diploid cell) , and as the (diploid cell) , and as the zygotes develop into diploid zygotes develop into diploid sporophytes, the cycle continues.sporophytes, the cycle continues.
Alternation of generationsAlternation of generations
The Green Algae(chlorophyta)The Green Algae(chlorophyta)
Have the same pigments as land Have the same pigments as land plantsplants
Have Have chlorophyll a and bchlorophyll a and b Marine algae are “macro”Marine algae are “macro” Reproduction-Reproduction-Alternation of Alternation of
generationsgenerations(2 or more separate (2 or more separate multicellular stages)multicellular stages)
motile ,have two apical or subapical motile ,have two apical or subapical flagellaflagella
AcetabulariaAcetabularia
CaulerpaCaulerpa spsp..
Caulerpa spCaulerpa sp..
Caulerpa floridanaCaulerpa floridana
Caulerpa racemosaCaulerpa racemosa
Caulerpa Caulerpa spsp..
Caulerpa sp.Caulerpa sp.
Chaetomorpha sp.Chaetomorpha sp.
Halimeda Halimeda sp.sp.
Udotea sp.Udotea sp.
Ventricularia sp.Ventricularia sp.
Ulva lactucaUlva lactuca
Life cycle Life cycle ulva sp.ulva sp.
Phaeophyta(brown algae)Phaeophyta(brown algae) Largest and most complex of the Largest and most complex of the
algaealgae All are marineAll are marine Have Have chlorophyll a chlorophyll a and and cc Brown color comes from accessory Brown color comes from accessory
pigments (pigments (fucoxanthinfucoxanthin))
have evolved an interesting type of alternation of generations, in which physiologically independent haploid gametophyte plants produce gametes, the fusion of which initiates the diploid sporophyte generation.
DictyotaDictyota
FucusFucus
LaminariaLaminaria
PadinaPadina
TurbinariaTurbinaria
SargassumSargassum
KelpKelp
Life cycle fucusLife cycle fucus
Rhodophyta(red algae)Rhodophyta(red algae) Greek word “Rhodos” = Greek word “Rhodos” = RedRed Have Have chlorophyll achlorophyll a and and dd Accessory Accessory pigment phycoerythrin pigment phycoerythrin gives the gives the
red color plus allows them to survive at red color plus allows them to survive at greater depths.greater depths.
Phycoerythrins are also found in cyanobacteriaPhycoerythrins are also found in cyanobacteria not flagellated; none has motile cells of any not flagellated; none has motile cells of any
kind.kind. extremely complex, involving one haploid extremely complex, involving one haploid
phase and two diploid phasesphase and two diploid phases
HalimeniaHalimenia sp. sp.
Halimenia sp.Halimenia sp.
RenouxiaRenouxia sp. sp.
RhodogrodonRhodogrodon sp.sp.
SebdeniaSebdenia sp. sp.
TrichoglowiaTrichoglowia sp. sp.
Corraline red algaCorraline red alga
HydrolythonHydrolython sp. sp.
PeyssonelliaPeyssonellia sp. sp.
Life cycle red algaeLife cycle red algae