Red algae differs from green and brown algae in

Options

A. (a) No chlorophyll a
B. (b) No differentiated cells
C. (c) No phycocyanin within their cells
D. (d) No flagellated stages in their life cycles

Answer

To answer the question "Red algae differs from green and brown algae in," we need to analyze the characteristics of red algae in comparison to green and brown algae. Here’s a step-by-step breakdown of the differences:

### Step 1: Identify the Types of Algae
- **Red Algae (Rhodophyta)**: Characterized by the presence of phycoerythrin, which gives them their red color.
- **Green Algae (Chlorophyta)**: Contain chlorophyll a and b, giving them a green color.
- **Brown Algae (Phaeophyta)**: Contain chlorophyll a and c, along with fucoxanthin, which gives them a brown color.

### Step 2: Analyze the Presence of Chlorophyll
- All three types of algae (red, green, and brown) contain chlorophyll a.
- Green algae have chlorophyll b, and brown algae have chlorophyll c, but red algae do not have chlorophyll b or c.

### Step 3: Examine the Presence of Differentiated Cells
- Algae, including red, green, and brown, typically do not have differentiated cells. They have a simple thallus structure.

### Step 4: Investigate the Presence of Phycocyanin
- Phycocyanin is a pigment found in blue-green algae (cyanobacteria) and is not present in red algae. However, it is not a defining characteristic of red algae as it is not found in green or brown algae either.

### Step 5: Consider the Life Cycle and Motility
- Red algae do not have flagellated stages in their life cycle, meaning they do not produce motile spores.
- In contrast, both green and brown algae have flagellated spores, which are motile.

### Conclusion
Based on the analysis, the correct answer to the question is that red algae differ from green and brown algae in that they do not have flagellated stages in their life cycle.

### Final Answer
**Red algae differs from green and brown algae in that they do not have flagellated stages in their life cycle.**

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