Answer:
RED algae help to form coral reefs.
Red algae contains the pigment phycoerythrin which gives out the red color of the algae; it absorbs blue light and reflects red light.
The Red algae that help to form coral reefs is the coralline algae. The coralline algae secretes a hard shell of carbonate around themselves, which in turn becomes a part of the coral reefs.
Explanation:
