Centric discoid form of diatom is

Options

A. Diploneis
B. Coscinodiscus
C. Stephanodiscus
D. Camphyloneis.

Answer

To solve the question regarding the centric discoid form of diatom, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Diatoms**: Diatoms are unicellular organisms that belong to the kingdom Protista. They are primarily photosynthetic and are often referred to as phytoplankton.

2. **Identify Characteristics**: Diatoms have a unique cell wall known as a frustule, which is made of silica. This frustule is porous and tough, allowing them to survive in aquatic environments. They do not have specialized locomotory organs and move with water currents.

3. **Classification of Diatoms**: Diatoms are classified into two main types based on their symmetry:
- **Centric Diatoms**: These have radial symmetry.
- **Pinnate Diatoms**: These have bilateral symmetry.

4. **Analyze the Options**: The question provides four options for the centric discoid form of diatoms:
- A) Diplonaceous
- B) Consinodiscus
- C) Staphnodiscus
- D) Campyloneusis

5. **Determine the Correct Option**: Since we are looking for the centric form, we need to identify which of the options corresponds to this classification.
- **Option A (Diplonaceous)**: Incorrect, as it does not represent a centric diatom.
- **Option B (Consinodiscus)**: Correct, as it is a type of centric diatom.
- **Option C (Staphnodiscus)**: Incorrect, as it does not represent a centric diatom.
- **Option D (Campyloneusis)**: Incorrect, as it does not represent a centric diatom.

6. **Conclusion**: The correct answer is **Option B: Consinodiscus**, which represents the centric discoid form of diatom.

### Final Answer:
The centric discoid form of diatom is **Consinodiscus**.

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