Prepared by :Prepared by :

Km. Monika BalmikiKm. Monika Balmiki

KV GANGTOKKV GANGTOK

The study of ALGAE is called The study of ALGAE is called “Phycology”“Phycology”

1.1. Chlorophyl- bearing plants, Chlorophyl- bearing plants,

2.2. Thalloid , Thalloid ,

3.3. Autotrophic & Aquatic.Autotrophic & Aquatic.

HABITATSHABITATS

A)Aquatic ( Fresh water & marine) MoistA)Aquatic ( Fresh water & marine) Moist stones, Soils and Wood.stones, Soils and Wood.B) Association with Fungi e.g. Lichen andB) Association with Fungi e.g. Lichen and animals e.g. Sloth bear animals e.g. Sloth bear C) Marine forms are Sea WeedsC) Marine forms are Sea WeedsD) Fresh water Algae D) Fresh water Algae – – Microscopic, Unicellular e.g. ChlamydomonasMicroscopic, Unicellular e.g. Chlamydomonas - Colonial forms e.g. Volvox- Colonial forms e.g. Volvox - Filamentous forms e.g. Ulothrix & Spirogyra. - Filamentous forms e.g. Ulothrix & Spirogyra.

REPRODUCTIONREPRODUCTION

Vegetative – by fragmentation. FragmentsVegetative – by fragmentation. Fragments develops into thallus.develops into thallus. Asexual - produce different type of sporesAsexual - produce different type of spores (zoospores)(zoospores) - Zoospores – Flagellated motile- Zoospores – Flagellated motile and germination gives rise to newand germination gives rise to new plants.plants.

Sexual Reproduction – fusion of two gemetsSexual Reproduction – fusion of two gemets

1. Isogamous – Flagellated similar in size 1. Isogamous – Flagellated similar in size e.g. chlamydomonase.g. chlamydomonas

- Non-flagellated but similar in- Non-flagellated but similar in size e.g. spirogyra.size e.g. spirogyra.2. Anisogamous – two gemets dissimilar in size2. Anisogamous – two gemets dissimilar in size e.g. chlamydomonas.e.g. chlamydomonas.3. Oogamous3. Oogamous - Fusion between one large, - Fusion between one large, non-motile – female gemete.non-motile – female gemete. smaller motile- male gametesmaller motile- male gamete e.g. Volvox, Fucus.e.g. Volvox, Fucus.

Isogamous Anisogamous

Oogamous

CLASSES OF ALGAECLASSES OF ALGAE

The Algae are divided into three mail The Algae are divided into three mail Classes:Classes:

1.1. ChlorophyceaeChlorophyceae

2.2. PhaeophyceaePhaeophyceae

3.3. RhodophyceaeRhodophyceae

CHLOROPHYCEAECHLOROPHYCEAE( Green Algae)( Green Algae)

Plant Body - unicellular, Colonial orPlant Body - unicellular, Colonial or FilamentousFilamentous Rigid Cell Wall – Inner layer – CelluloseRigid Cell Wall – Inner layer – Cellulose - Outer layer – Pectose- Outer layer – Pectose Green due to chlorophyll a & bGreen due to chlorophyll a & b Definite chloroplasts – Discoid, Plate-like reticulate, Definite chloroplasts – Discoid, Plate-like reticulate,

cup- shaped,spiral or ribbon-shapedcup- shaped,spiral or ribbon-shaped

Storage bodies - Pyrenoids, located in the Storage bodies - Pyrenoids, located in the chloroplasts. Store food in thechloroplasts. Store food in the form of oil dropletsform of oil droplets

VOLVOX CHLAMYDOMONAS

ULVA

Chlorophyceae -ReproductionChlorophyceae -Reproduction

The Sex organs are always unicellularThe Sex organs are always unicellular

1.1. Vegetative – Fragmentation(spores)Vegetative – Fragmentation(spores)

2.2. Asexual Reproduction – Flagellated zoosporesAsexual Reproduction – Flagellated zoospores

3.3. Sexual Reproducion – isogemous,Sexual Reproducion – isogemous,

anisogemous andanisogemous and

oogamousoogamous

PhaeophyceaePhaeophyceae(Brown Algae)(Brown Algae)

Marine habitats Marine habitats Plant body attached to the substratum by a Hold fast, Plant body attached to the substratum by a Hold fast,

Stalk –Stipe, Leaf Like- Photosynthetic organ – FrondStalk –Stipe, Leaf Like- Photosynthetic organ – Frond Golden brown – Xanthophyll pigment fucoxanthin in Golden brown – Xanthophyll pigment fucoxanthin in

their chromotophores. Addition to chlo.a, chlo.c and their chromotophores. Addition to chlo.a, chlo.c and carotenoids.carotenoids.

Accumulation of reserve food as fats and oil rather then Accumulation of reserve food as fats and oil rather then starch.starch.

The cellulosic wall covered by algin The cellulosic wall covered by algin Centrally located vacuole and nucleus.Centrally located vacuole and nucleus.

LAMINARIA DICTYOTA

SARGASSUM

Phaeophyceae- ReproductionPhaeophyceae- Reproduction

Vegetative reproduction – FragmentationVegetative reproduction – Fragmentation Asexual Reproduction - biflagellateAsexual Reproduction - biflagellate

zoozpores (two unequal)zoozpores (two unequal) Sexual Reproduction - Isogamous,Sexual Reproduction - Isogamous,

anisogamous or oogamous.anisogamous or oogamous.

- Union of gamets takes- Union of gamets takes

place in water or within the oogonium.place in water or within the oogonium.

RhodophyceaeRhodophyceae(Red Algae)(Red Algae)

Red Pigment, r-phycoerythrin in their bodyRed Pigment, r-phycoerythrin in their body Found in the warmer areasFound in the warmer areas Red thalli – MulticellularRed thalli – Multicellular The food stored as floridden starchThe food stored as floridden starch

PORPHYRAGRACILARIA

GELIDIUM

Rhodophyceae-ReproductionRhodophyceae-Reproduction

Vegetative Reproduction – FragmentationVegetative Reproduction – Fragmentation Asexual – Non-motile sporesAsexual – Non-motile spores Sexual - Non-motile gamets (oogamous)Sexual - Non-motile gamets (oogamous)

e.g. Polysiphonia, porphyra etc.e.g. Polysiphonia, porphyra etc.

Algae- Economic ImportanceAlgae- Economic Importance

Use as Food e.g. Porphyra, Laminaria &Use as Food e.g. Porphyra, Laminaria &

Sargassum.Sargassum. Certain marine brown & red algae produce large Certain marine brown & red algae produce large

amount of hydrocolloids (water holding substances)amount of hydrocolloids (water holding substances) Algin – brown algae e.g. sargassumAlgin – brown algae e.g. sargassum Agar used to grow microbs and preparation of Agar used to grow microbs and preparation of

icecream and jellies e.g. Gelidium & Gracilaria.icecream and jellies e.g. Gelidium & Gracilaria. Rich proteins – Chlorella & SpirullinaRich proteins – Chlorella & Spirullina