Which of the following algal groups has no motile stage

Options

A. Brown
B. Yellow
C. Red
D. Green

Answer

To determine which algal group has no motile stage, we can analyze each of the options provided:

1. **Brown Algae (Phaeophyceae)**:
- Brown algae are known to have a motile reproductive phase. Specifically, they produce gametes that are flagellated and capable of movement. Therefore, this group does have a motile stage.

2. **Yellow Algae (Chrysophyceae)**:
- Yellow algae may also have motile stages, particularly in their reproductive phases. They can produce flagellated cells, which means they are not entirely non-motile.

3. **Red Algae (Rhodophyceae)**:
- Red algae are characterized by the absence of any motile stage. They do not produce flagellated cells at any point in their life cycle. This means that red algae are completely non-motile.

4. **Green Algae (Chlorophyceae)**:
- Green algae can be either motile or non-motile, as they include both flagellated unicellular forms and non-flagellated forms. Thus, they do have motile stages.

Based on this analysis, the algal group that has no motile stage is **Red Algae (Rhodophyceae)**.

**Final Answer**: Red Algae (Rhodophyceae)

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