Occurance and Habitat :
Nostoc is common tarrestrial and sub aerial bacterium.It is widely distributed in alkaline soil and moist rocks.
Vegetative structure :
Nostoc colony form jelly like mass.Many filaments are embedded in this mass.The individual filament is called trichome.Trichome is and unbranched and appears bead like. structure.
Structure of cells :
The individual cells are spherical.Some cells are barrel shaped and cylinderical.All the cells in trichome are similar in structure.some slightly large,rounded,light yellow and thick walled cell are present at intervals.These cells are called heterocysts.
Reproduction :
They lack sexual reproduction they carry out only asexual reproduction in thei rlife cycle.
Fragmentation : Hormogonia are formed by fragmentation.The filament brake at different points and each broken part is called hormogonia.Hormogonia grow and form new filament.Filaments are break by death and decay of ordinary cells.Hetericysts may form breaking point.
Akinetes : Akinetes are thick walled enlarge reproductive cells.They are specialized reproductive cells.They store food and become resting cells.They grow under favorable conditions.
Nostoc is common tarrestrial and sub aerial bacterium.It is widely distributed in alkaline soil and moist rocks.
Vegetative structure :
Nostoc colony form jelly like mass.Many filaments are embedded in this mass.The individual filament is called trichome.Trichome is and unbranched and appears bead like. structure.
Structure of cells :
The individual cells are spherical.Some cells are barrel shaped and cylinderical.All the cells in trichome are similar in structure.some slightly large,rounded,light yellow and thick walled cell are present at intervals.These cells are called heterocysts.
Reproduction :
They lack sexual reproduction they carry out only asexual reproduction in thei rlife cycle.
Fragmentation : Hormogonia are formed by fragmentation.The filament brake at different points and each broken part is called hormogonia.Hormogonia grow and form new filament.Filaments are break by death and decay of ordinary cells.Hetericysts may form breaking point.
Akinetes : Akinetes are thick walled enlarge reproductive cells.They are specialized reproductive cells.They store food and become resting cells.They grow under favorable conditions.
Nostoc : A cynaobacterium
Reviewed by M.Zulqarnain
on
22:58
Rating:
Reviewed by M.Zulqarnain
on
22:58
Rating:
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