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 determine which group of algae does not have motile stages in their life cycle, we need to analyze the characteristics of each type of algae mentioned in the options.

### Step-by-Step Solution:

1. **Identify the Types of Algae**:
- The options given are red algae, green algae, brown algae, and blue-green algae (cyanobacteria).
- Red algae belong to the class Rhodophyceae.
- Green algae belong to the class Chlorophyceae.
- Brown algae belong to the class Phaeophyceae.
- Blue-green algae are classified as cyanobacteria.

2. **Examine the Reproductive Modes**:
- **Red Algae (Rhodophyceae)**:
- They do not have motile spores or gametes. The reproductive units are non-motile.
- They primarily reproduce asexually through fragmentation, fission, or budding.
- **Green Algae (Chlorophyceae)**:
- They can have both motile and non-motile spores. Many green algae produce flagellated gametes, making them motile.
- **Brown Algae (Phaeophyceae)**:
- They also produce motile spores. The spores are flagellated and can swim.
- **Blue-Green Algae (Cyanobacteria)**:
- They primarily reproduce asexually and do not produce motile spores. The spores formed are non-motile.

3. **Analyze the Options**:
- **Option A**: Red algae and green algae - Incorrect, as green algae have motile stages.
- **Option B**: Red algae and brown algae - Incorrect, as brown algae have motile stages.
- **Option C**: Red algae and blue-green algae - Correct, as both do not have motile stages.
- **Option D**: Green algae and brown algae - Incorrect, as both have motile stages.

4. **Conclusion**:
- The correct answer is **Option C: Red algae and blue-green algae**, as neither of these groups has motile spores or gametes in their life cycle.