Motile stages are not found in life cycle of :-

Options

A. Red Algae & green Algae
B. Red Algae & brown Algae
C. Red Algae & blue green Algae
D. Green Algae & brown Algae

Answer

To solve the question regarding which group of organisms does not have motile stages in their life cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Motile Stages**:
- Motile stages refer to the phases in the life cycle of an organism where the cells or spores can move, typically facilitated by flagella or cilia.

2. **Identify the Groups Mentioned**:
- The question mentions different groups of algae: Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae).

3. **Analyze the Motility of Each Group**:
- **Chlorophyta (Green Algae)**: Generally, green algae possess flagella (2 to 8) in their motile stages, allowing them to move.
- **Phaeophyta (Brown Algae)**: Brown algae typically have 2 laterally arranged flagella in their motile stages, which also allows for movement.
- **Rhodophyta (Red Algae)**: Red algae do not have flagella in their life cycle, meaning they do not have motile stages.

4. **Consider Other Organisms**:
- The question also mentions blue-green algae (BGA), which are actually prokaryotic organisms (eubacteria). They do not have flagella either, and thus also lack motile stages.

5. **Conclusion**:
- Based on the analysis, both red algae (Rhodophyta) and blue-green algae (BGA) do not have motile stages in their life cycles. Therefore, the correct answer to the question is **red algae and blue-green algae**.

### Final Answer:
The motile stages are not found in the life cycle of **red algae and blue-green algae**.

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