In phaeophycaee, the vegetative cells have a cellulosic cell wall usually ocovered on the outside by a gelatinous coating of _____

Answer

**Step-by-Step Text Solution:**

1. **Understanding Phaeophyceae**: Phaeophyceae, commonly known as brown algae, are a group of photosynthetic organisms found in marine environments. They have distinct cellular structures.

2. **Cell Structure**: The vegetative cells of Phaeophyceae possess a cellulosic cell wall. This means that the primary component of their cell wall is cellulose, which is a common structural polysaccharide found in plants.

3. **Outer Coating**: In addition to the cellulosic cell wall, these vegetative cells are covered on the outside by a gelatinous coating. This coating serves various functions, including protection and maintaining moisture.

4. **Composition of the Gelatinous Coating**: The gelatinous coating is primarily made up of substances known as phycocolloids. These are polysaccharides that provide the gelatinous texture.

5. **Examples of Phycocolloids**: The specific phycocolloids that are commonly found in the gelatinous coating of brown algae include algin and phycoidin. These substances are important for the structural integrity and functionality of the algae.

6. **Final Answer**: Therefore, the vegetative cells of Phaeophyceae have a cellulosic cell wall that is usually covered on the outside by a gelatinous coating of **phycocolloids**.

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