Which is a phaeophycean alga

Options

A. Gelidium
B. Polysiphonia
C. Porphyra
D. Laminaria

Answer

To determine which of the given options is a phaeophycean alga (brown algae), we can follow these steps:

### Step 1: Understand the Classification
Phaeophyceae, commonly known as brown algae, are a group of algae characterized by their brown color due to the presence of the pigment fucoxanthin. They are primarily found in marine environments.

### Step 2: Analyze the Options
We have the following options:
- A. Gelidium
- B. Polysiphonia
- C. Porphyra
- D. Laminaria

### Step 3: Identify the Characteristics of Each Option
- **Gelidium**: This is a type of red algae (Rhodophyceae).
- **Polysiphonia**: This is also a red algae (Rhodophyceae).
- **Porphyra**: This is another example of red algae (Rhodophyceae).
- **Laminaria**: This is a well-known example of brown algae (Phaeophyceae).

### Step 4: Conclusion
Since Laminaria is the only option that belongs to the phaeophycean group, the correct answer is:
**D. Laminaria**