Which of the following is centric type golden brown photosynthetic protist with radial symmetry?

Options

A. Melosira
B. Navicula
C. Ceratium
D. Pyrocystis

Answer

To solve the question "Which of the following is a centric type golden brown photosynthetic protist with radial symmetry?", we can follow these steps:

### Step 1: Understand the Key Terms
- **Centric type**: This refers to organisms that have a radial symmetry, typically seen in diatoms.
- **Golden brown**: This indicates the color of the organism, which is often due to the presence of specific pigments like fucoxanthin.
- **Photosynthetic protist**: This means we are looking for a protist that can perform photosynthesis.
- **Radial symmetry**: This means the organism can be divided into similar halves by multiple planes passing through the central axis.

### Step 2: Identify the Characteristics
We need to find an organism that:
1. Belongs to the protista kingdom.
2. Is photosynthetic.
3. Exhibits radial symmetry.
4. Is golden brown in color.

### Step 3: Consider Possible Organisms
In the context of protists, diatoms are a group that fits many of these characteristics. Specifically, the genus **Melosira** is known for being a centric diatom, which is golden brown and exhibits radial symmetry.

### Step 4: Conclusion
Based on the characteristics outlined, the organism that fits all the criteria of being a centric type golden brown photosynthetic protist with radial symmetry is **Melosira**.

### Final Answer
The correct answer is **Melosira**.

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