Which of the following is not a characteristic of brown algae ?

Options

A. Multicellularity
B. Presence of chlorophylls a and b
C. Lives along rocky coast
D. Harvested for commercial reasons

Explanation

**Step-by-Step Solution:**

1. **Identify the Group of Algae**: Brown algae belong to the group known as Pheophyta. This is important to understand their characteristics.

2. **Analyze the Options**: The options given are:
- A. Multicellularity
- B. Presence of chlorophylls A and B
- C. Lives along rocky coast
- D. Harvested for commercial reasons

3. **Evaluate Each Option**:
- **Option A: Multicellularity**: Brown algae are indeed multicellular and generally have a macroscopic size with a definite shape. Therefore, this is a characteristic of brown algae.
- **Option B: Presence of chlorophylls A and B**: While chlorophyll A is present in brown algae, chlorophyll B is primarily associated with green algae. Brown algae mainly contain the pigment fucoxanthin, which gives them their characteristic yellowish-brown color. This option is not a characteristic of brown algae.
- **Option C: Lives along rocky coast**: Brown algae are commonly found attached to rocks and reefs in marine environments, making this statement true.
- **Option D: Harvested for commercial reasons**: Many species of brown algae, such as Fucus, Laminaria, and Sargassum, are harvested for various commercial uses, confirming this statement as true.

4. **Determine the Correct Answer**: Since option B (presence of chlorophylls A and B) is not a characteristic of brown algae, it is the correct answer to the question.

**Final Answer**: The characteristic that is not associated with brown algae is the "presence of chlorophylls A and B."

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