Question

which is known as the filamentous blue green algae
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Answer 1

Spirogyra is the correct answer.

Answer 2

Answer:

Blue-green algae. Blue-green algae, also called cyanobacteria, any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms. ... Cyanobacteria may be unicellular or filamentous. Many have sheaths to bind other cells or filaments into colonies.

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