Which of the following are not a group of brown algae ?

Options

A. Sargassum and Fucus
B. Ectocarpus, Dictyota
C. Dictyota, Laminaria
D. Spirogyra and chara

Answer

To solve the question "Which of the following are not a group of brown algae?", we need to identify which of the given options do not belong to the brown algae category.

### Step-by-Step Solution:

1. **Understand what brown algae are**: Brown algae are a group of algae characterized by the presence of chlorophyll A and C, along with the pigment fucoxanthin, which gives them their brown color. Common examples include Sargassum, Fucus, Dictyota, and Laminaria.

2. **List the options provided**: The options given in the question are:
- Sargassum and Fucus
- Ectocarpus and Dictyota
- Dictyota and Laminaria
- Spirogyra and Cara

3. **Identify which options belong to brown algae**:
- **Sargassum and Fucus**: Both are well-known brown algae.
- **Ectocarpus and Dictyota**: Both are also classified as brown algae.
- **Dictyota and Laminaria**: Both belong to the brown algae group.
- **Spirogyra and Cara**: These are not brown algae; they are classified as green algae.

4. **Determine the correct answer**: Since Spirogyra and Cara do not belong to the brown algae group, they are the correct answer to the question.

### Final Answer:
The organisms that are not a group of brown algae are **Spirogyra and Cara**.

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