In which of the following cell wall is divided in two half parts :-

Options

A. Diatoms
B. Dinoflagellates
C. Euglenoids
D. Red algae

Answer

To determine which organism has a cell wall that is divided into two equal half parts, we can analyze the options provided. Here’s a step-by-step breakdown:

### Step 1: Understand the Structure of Cell Walls
- Cell walls can vary significantly among different organisms, particularly among protists like diatoms, dinoflagellates, euglenoids, and red algae.

### Step 2: Analyze Each Option
1. **Diatoms**:
- Diatoms have a unique cell wall made of silica (hydrated silicon dioxide).
- Their cell wall is divided into two equal parts, known as theca, specifically the epitheca (upper part) and hypotheca (lower part).
- This structure resembles a soap box with two lids, indicating bilateral symmetry.

2. **Dinoflagellates**:
- Some dinoflagellates have a cell wall, but it is primarily made of cellulose and does not exhibit the division into two equal parts like diatoms.

3. **Euglenoids**:
- Euglenoids do not possess a traditional cell wall. Instead, they have a pellicle, which is a flexible protein layer, meaning they do not have a cell wall divided into parts.

4. **Red Algae**:
- Red algae have a double cell wall but do not have a structure that divides it into two equal halves.

### Step 3: Conclusion
- Based on the analysis, the only organism among the options that has a cell wall divided into two equal parts is the **diatom**.

### Final Answer
- The answer is **Diatom**.

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