chlorophyta

Division : Chlorophyta
Order 3 : Ulotrichales
Family : Ulotrichaceae
Genus : Ulothrix
Order 4 : Zygnematales
Family : Zygnemataceae
Genus : Zygnema
G. : Spirogyra

Ulothrix

• generally found in fresh and marine water , The plant body consists of unbranched, uniseriate filaments.
• the basal cell is elongated and does not have chlorophyll. It is called the basal holdfast , which attaches the filament to the substratum . The other cells of the filaments are arranged end to end. They are barrel-shaped or cylindrical .
• Reproduction, asexual by fragmentation when Vegetative cells of Ulothrix break into small pieces accidentally. Each fragment develops into a new filament . and sexual by Akinete formation Some of the vegetative cells of Ulothrix are converted into thick walled akinetes. Food reserves are accumulated within the akinetes. When the conditions are favourable each akinete develops into a new plant.
• It have (H - shape ) chloroplast with two to many pyrenoids .
Spirogyra


• It is unbranched , spiral arrangement of the chloroplasts that is diagnostic of the genus (spiral shape ), Each chloroplast contains several pyrenoids .
• In spring Spirogyra grows, but when there is enough sunlight and warmth they produce large amounts of oxygen, adhering as bubbles between the tangled filaments