CYANOBACTERIA
The Cyanobacteria are the largest and the most diverse group of photosynthetic bacteria, these are
considered near to algae because of presence of chlorophyll-a and liberation of O2, similar to other
algal groups. They are commonly called the blue-green algae because of dominant blue
photosynthetic pigment in their chromatophores.
Habitat:
 The members of this class are commonly known as blue green algae.
 They are found in fresh water, ponds, ditches, drains and moist soils.
 A few species are endophytes, lives in the cavities of other plants, usually bryophytes, for
example Nostoc is found in the thallus of Anthoceros.
CELL TYPE:
They are true prokaryotes. They lack true nucleus and nuclear membrane.
SIZE AND SHAPE:
They are very greatly in size and shape. They range in diameter from 1 to 10µm.
VEGETATIVE (BODY) STRUCTURE:
They may be unicellular or form colonies of different shape or form filament. The filament is
composed of trichomes. Trichome is a chain of cell. Each filament is surrounded by mucilaginous
sheath
Cell wall:
They have gram negative type of cell wall.
LOCOMOTION:
They lack flagella. They use gas vesicle to move in the water.
PHOTOSYNTHETIC SYSTEM:
Its system resembles to eukaryotes. They have chlorophyll and photosystem 2. They use phycobilins
as necessary pigment. Phycocyanin is their predominant phycobilins. Cyanobacteria fix CO2 through
Calvin Cycle.
RESERVE FOOD MATERIAL:
Their reserve food material is glycogen.
REPRODUCTION:
 Binary fission
 Fragmentation
 Akinetes.
SUBMITTTED BY: IMRAN HAIDER