Question

nostoc and anabaena is an example of 1-)colonial BGA 2-) filamentous BGA​

Answer 1

Explanation:

A - heterocyst, B- Mucilagenous sheath.

The cyanobacteria (also referred to as blue-green algae)have chlorophyll a similar to green plants and are photosynthetic autotrophs. The cyanobacteria are unicellular, colonial or filamentous fresh-water marine or terrestrial algae. The colonies are generally surrounded by a gelatinous sheath. They often form blooms in polluted water bodies. Some of these organisms can fix atmospheric nitrogen in specialized cells called heterocysts, e.g Nostoc and Anabaena.

So the correct option is "A - heterocyst, B- Mucilagenous sheath" hope it helps you make brainliast answer.