What are diatoms, chitin and heterocyst

Asked by harinder | 27th Aug, 2008, 04:44: PM

Expert Answer:

Chitin is a tough complex sugar. They form the cell wall of fungi.

Heterocysts are specialized nitrogen-fixing cells formed by some filamentous cyanobacteria, such as Nostoc punctiforme and Anabaena sperica during nitrogen starvation. They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis.. These cells are large and thick-walled . They occurs at intervals along the filaments of these cyanobacteria.

Diatoms belong to kingdom Protista. They are a group of unicellular, microscopic algae that have rigid cell walls composed of silica. These reproduce asexually and may be marine or freshwater.

Answered by  | 27th Aug, 2008, 06:14: PM

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