Which of the following algae are rich sources of iodine?

Options

A. Polysiphonia and Dictyota
B. Laminaria and Fucus
C. Sargassum and Ectocarpus
D. Spirulina and Spirogyra

Answer

To determine which algae are rich sources of iodine, we can analyze the options provided in the question step by step.

### Step 1: Understand the options
The options given are:
1. Polysiphonia and Dictyota
2. Laminaria and Fucus
3. Sargassum and Ectocarpus
4. Spirulina and Spirogyra

### Step 2: Identify the types of algae
- **Polysiphonia**: A red algae.
- **Dictyota**: A brown algae.
- **Laminaria**: A brown algae, commonly known as kelp.
- **Fucus**: Another type of brown algae.
- **Sargassum**: A brown algae.
- **Ectocarpus**: A brown algae.
- **Spirulina**: A cyanobacteria, often referred to as blue-green algae.
- **Spirogyra**: A green algae.

### Step 3: Research iodine content in algae
From biological studies, we know that certain brown algae are particularly rich in iodine. Specifically, Laminaria and Fucus are known for their high iodine content.

### Step 4: Analyze the options for iodine content
- **Polysiphonia and Dictyota**: Not known for high iodine content.
- **Laminaria and Fucus**: Known to contain about 25% iodine and are widely recognized as rich sources.
- **Sargassum and Ectocarpus**: While they are brown algae, they are not specifically noted for high iodine content.
- **Spirulina and Spirogyra**: These are not significant sources of iodine.

### Step 5: Conclusion
Based on the analysis, the algae that are rich sources of iodine are **Laminaria and Fucus**. They are brown algae and are often used in medicine due to their iodine content, particularly for treating conditions like goiter.

### Final Answer
The correct answer is **Laminaria and Fucus**.

---