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Give a short note on chlorophyceae
Chlorophyta are today classified under the Kingdom Protocista , Under the Phylum Viridiplantae,often called Phylum Algae.Chlorophyta are found in many moist non-aquatic habitats, including snow banks. Chlorophytic algae have been found up to 70 feet deep in the Antarctic ice sheet in a dormant state Epiphytic epizoic forms are also present. These occur on larger algae like seaweed or on the bark of the shaded side of trees.
.Aquatic forms are usually filamentous, or unicellular, and may be planktonic (free-floating) or attached to rocks along the shore. Larger , non-filamentous forms of chlorophyta are usually marine,while its freshwater forms are filamentous. Chlorophyta are the only known division whose species contribute to lichen formation.Very few parasitic forms of chlorophytes are known, one example being the species Cephaleuros, of the orderChaetophorales.

The "Thallus" is the vegetative structure formed by all species of Algae in their life cycles.Chlorophyta species occur as unicellular organisms, multicellular organisms or as colonies of  unicellular organisms bound by a gel like matrix.The thalli of chlorophytes may vary from minute unicells , a micron or two in diameter to a few feet long, stranded structure. It may be motile or non-motile.
The Cell wall usually consists of two layers. The inner layer is firm , composed of cellulose,while the outer layer is gelatinous , often with pectin embedded in the matrix. Some unicellular flagellates, however, lack a cell wall but posses a wall-like structure called "the lorica". Lorica do not completely enclose the cell and are not completely in contact with the cell. The space between the plasma membrane and the lorica is filled either with water or with a gelatinous matrix similar to that found in the outer layer of walled chlorophytes. Chloroplasts are present in all cells , and vary is shape and number but are usually consistent within a given species.Grana  are absent in algal chloroplasts, but thylakoids are present containing a central lipid layer with a large number of pigment molecules embedded in it. No pigments other than the chlorophylls, and the typical xanthophylls and carotenes are found within the chlorophytes. Allchlorophytes are not flagellated, most unicellular and colonialforms posses flagella. Flagella are of the
whiplash (acronematic) type, and all consist of the 9+2microtubule pattern.
 
At the base of the flagellum, is an organelle called the blepharoplast, a structure analogous to the centriole in animal cells. Its function is thought to be anchorage of the flagellum to the cyto-skeleton and well as a role in the action of the flagellum..


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