cyanophyta

Algae are a very large and diverse group of eukaryotic organisms simple, typically autotrophic organisms, ranging from unicellular genera such as Chlorella to multicellular forms such as the giant kelp that grow to 65 meters in length . All true algae therefore have a nucleus enclosed within a membrane and plastids bound in one or more membranes. Algae exhibit a wide range of reproductive strategies, from simple, asexual cell division to complex forms of sexual reproduction.
Algae lack the various structures that characterize land plants, such as the leaf-like phyallids of bryophytes, rhizoids in nonvascular plants, and the roots, leaves, and other organs that are found in tracheophytes (vascular plants).
Distinctive character of Algae :
1- The algae are chlorophyll bearing organism with a thallus like plant body .
2- Thalli (singular : thallus) lack vascular tissue and epidermis with stomata .
3- There is no embryo formation after gametic union .
*** Prokaryotic Algae (Cyanophyta ) ***
Cyanophyta can be found in almost every terrestrial and aquatic habitat—oceans, fresh water, damp soil, temporarily moistened rocks in deserts. Cyanophyta include unicellular and colonial species. Colonies may form filaments, sheets Some filamentous colonies show the ability to differentiate into several different cell types: vegetative cells, the normal, photosynthetic cells that are formed under favorable growing conditions; akinetes, the climate-resistant spores that may form when environmental conditions become harsh; and thick-walled heterocysts .
Prokaryotic Algea (Cyanophyta )
Pigment : chlorophyll a, Biliprotein ( phycoerythrin &phycocyanin).
Food reserves : Cyanophycin starch & cyanophycin protein .
Division : Cyanophyta .
Order 1 :Chroococcales
Family 1 : Chroococcaceae
Genus : Chroococcus
Merismopedia
Family 2 : Microcystaceae
Genus : Gloeocapsa
Microcystis

Order 2 : Oscillatoriales ( Harmogonales)
Family1 : Oscillatoriaceae
Genus :Oscillatoria
Family2 : Rivulariaceae
Genus : Rivularia
Gloeotrichia
Family 3 :Nostocaceae
Genus :Nostoc
Anabaena

Chroococcus
Division : Cyanophyta
Order 1 :Chroococcales
Family 1 : Chroococcaceae
Genus : Chroococcus


a unicellular organism, cells are ovoid or rod-shaped ,usually found in colonies of two, four, or eight cells with a transparent protective covering sheath containing photosynthetic pigments. Chroococcus is an autotrophic organism able to survive almost without any freshwater or oxygen source (Carboni) , it uses an extensive quantity of atmospheric carbon for photosynthetic processes, creating free oxygen to be used by other organisms .. It produces oxygen and adenosine triphosphate (ATP) through photosynthetic methods using sunlight as the catalyst.