General Characteristics of Chlorophyceae (Green Algae)
Grass green chromatophores.
Presence of starch as reserve food
Members of green algae mostly green in fresh water, a few in brackish and saline water and few are terrestrial.
They show wide range of variations in their thallus structure like unicellular motile (Chlamydomonas), Coenobium(Volvox), palmelloid (Tetrospora), non motile (Chlorella), Dendroid (Ecballocystis), filamentous branched (Cladophora) and unbranched (Spirogyra), heterotrichous (Coleochaete), siphonaceous (Vaucheria) and parenchymatous (Ulva) .
Flagella are 1 -many, equal in size inserted either subapically, apically. Flagella shows 9 +2 arrangement when viewed under Electron microscope.
The cells are eukaryotic in nature. Usually there is only one nucleus in each cells, but in siphonales and cladophorales many nuclei are present.
The cell wall is made up of cellulose consist of hydroxyproline glycosides Or xylans and mannans. In Chara cell wall is encrusted with calcium and magnesium carbonate.
The cytoplasm contains many small vacuoles which pushes with cytoplasm towards periphery and called primordial urtical.
The main pigments are chlorophyll A, chlorophyll B, some carotenes and xanthophylls.
They reproduce by three methods I. e. Vegetative method, asexual method, sexual method.
Normally haploid phase is dominant phase and there is haplontic alternation of generation.
Vegetatively by cell division, fragmentation; Asexual by zoospore, aplanospore, akinete etc. and sexually by isogamy to oogamy.
The sexual reproduction is absent in some members Chlorococcales.
The zygote is only diploid structure in lifecycle.