Question

Gracilaria is a

• A. Brown algae
• B. Green algae
• C. Red algae
• D. None

Hint:

Remember the two main commercial agarophytes: Gracilaria and Gelidium.
Both are red algae (Rhodophyta).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Seaweeds (marine macroalgae) are classified into three major taxonomic groups based on their principal photosynthetic pigments: Chlorophyta (green), Phaeophyta (brown), and Rhodophyta (red).

Step 2: Detailed Explanation:
Gracilaria is a genus of red algae (Rhodophyta) found in warm, coastal marine waters.
Its cells contain phycobiliproteins (phycoerythrin), which give it a red appearance by absorbing blue-to-green light.
It is highly valuable as an "agarophyte" because it is a primary source of agar-agar, a hydrocolloid used as a gelling agent in foods, pharmaceuticals, and microbial culture media.

Step 3: Final Answer:
Gracilaria is a Red algae.