Select the incorrect statement w.r.t. Dictyota.

Options

A. Food is stored in the form of mannitol
B. Vegetative cells have coating of algin,surrounding the cellulosic wall
C. Zoospores are pyriform and bear two equal laterally attached fiagella
D. It is marine alga

Answer

To solve the question of identifying the incorrect statement with respect to Dictyota, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Identify the Classification of Dictyota**:
- Dictyota belongs to the group Pheophyceae, which are commonly known as brown algae. This classification is essential to understand the characteristics of Dictyota.

**Hint**: Remember that Dictyota is classified under brown algae.

2. **Evaluate the First Statement**:
- The first statement claims that food is stored in the form of mannitol. This is correct because brown algae, including Dictyota, store food as mannitol or laminarin.

**Hint**: Recall that brown algae store food in complex carbohydrates.

3. **Evaluate the Second Statement**:
- The second statement mentions that vegetative cells have a coating of algin surrounding the cellulosic wall. This is also correct, as algin is a hydrocolloid that surrounds the cell walls of Dictyota.

**Hint**: Algin is important for water retention and has commercial uses.

4. **Evaluate the Third Statement**:
- The third statement states that zoospores are piriform and have two equal laterally attached flagella. This is incorrect because zoospores of Dictyota are indeed piriform (pear-shaped), but they possess two unequal flagella, not equal.

**Hint**: Focus on the shape and characteristics of the flagella associated with zoospores.

5. **Evaluate the Fourth Statement**:
- The fourth statement asserts that Dictyota is a marine algae. This is correct, as Dictyota is found in marine environments.

**Hint**: Consider the habitat of Dictyota.

6. **Conclusion**:
- After evaluating all the statements, the incorrect statement is the third one, which incorrectly describes the flagella of zoospores as equal instead of unequal.

### Final Answer:
The incorrect statement with respect to Dictyota is: **"Zoospores are piriform and have two equal laterally attached flagella."**