What is incorrect for brown algae

Options

A. Presence of chlorophyll a and chlorophyll c
B. Occurrence of fucoxantium
C. Presence of chlorophyll a and chlorophyll b
D. Attachment to substratum.

Answer

### Step-by-Step Solution:

1. **Understanding Brown Algae**: Brown algae are a group of marine organisms classified under the class Phaeophyceae. They are primarily found in marine environments and are characterized by their brown color.

2. **Identifying the Options**: The question provides four options regarding the characteristics of brown algae:
- A. Presence of chlorophyll A and chlorophyll C
- B. Occurrence of fucoxanthin
- C. Presence of chlorophyll A and chlorophyll B
- D. Attachment to substratum

3. **Analyzing Each Option**:
- **Option A**: Brown algae do contain chlorophyll A and chlorophyll C. This statement is correct.
- **Option B**: Fucoxanthin is a pigment found in brown algae that gives them their characteristic color. This statement is correct.
- **Option C**: Brown algae do not contain chlorophyll B; instead, they have chlorophyll A and chlorophyll C. Therefore, this statement is incorrect.
- **Option D**: Brown algae are typically attached to a substratum, which means they are mostly sessile. This statement is correct.

4. **Conclusion**: Since option C states the presence of chlorophyll A and chlorophyll B, which is not true for brown algae, it is the incorrect statement.

5. **Final Answer**: The incorrect option for brown algae is **C**: Presence of chlorophyll A and chlorophyll B.