Algae
Algae are chlorophyll-bearing, simple, thalloid, autotrophic and largely aquatic (both fresh water and marine) organisms.
Habitat
moist stones
soils
wood
in association with fungi (lichen) and animals (e.g on sloth bear)
Reproduction methods
Vegetative
A. Reproduction
S. Reproduction (fusion of 2 gametes)
Fragmentation - each fragment develops into a thallus.
By production of different types of spores, most common - zoospores.
Flagellated (motile)
On germination gives rise to new plants.
Isogamous
Flagellated and similar in size (Ulothrix)
Non-flagellated (non-motile)
but similar in size (Spirogyra)
anisogamous
. Fusion of two gametes dissimilar in size (Eudorina)
Oogamous, e.g., Volvox, Fucus.
Fusion between one large, non - motile female gamete & a smaller, motile male gamete
chlorophyceae
green algae
plant body
colonial (many cells grouped as a colony)
filamentous (filament or thread like structure)
unicellular
chloroplasts
discoid,
plate-like
reticulate
cup-shaped
spiral
ribbon-shaped
its grass green coz of chlorophyll a and b
one or more storage bodies
called pyrenoids located here
Pyrenoids contain protein
besides starch
a rigid cell wall - inner layer of cellulose
& an outer layer of pectose.
Vegetative reproduction - fragmentation or thru different types of spores.
Chlamydomonas, Volvox, Ulothrix, Spirogyra and Chara
A. reproduction is by flagellated zoospores produced in zoosporangia.
S. reproduction may be isogamous, anisogamous or oogamous