Question

why is cyanobacteria called blue green algae

Answer 1

because they prepare their own food

Answer 2

Heya...

Here is your answer....

Cyanobacteria is called blue green algae.

Because it contains the chlorophyll and photocyanin.

The chlorophyll gives green colour and photocyanin gives blue colour to the cyanobacteria.

So it is in blue and green colour.

So it is called blue green algae.