dinophycean theca is made of

Options

A. Silica
B. Lime
C. Cellulose
D. Protein

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the composition of the theca in dinophyceans (dinoflagellates). The theca is the outer layer or covering of these organisms.

2. **Identifying Dinoflagellates:**
Dinoflagellates are unicellular eukaryotes that belong to the phylum Protista. They are primarily found in marine environments and can be autotrophic (capable of photosynthesis) or heterotrophic (feeding on other organisms).

3. **Analyzing the Options:**
The options provided are:
- A) Silica
- B) Lime
- C) Cellulose
- D) Protein

4. **Determining the Composition of the Theca:**
- **Silica**: This is primarily found in diatoms, not dinoflagellates.
- **Lime**: This is not a component of dinoflagellate theca.
- **Cellulose**: The outer layer of dinoflagellates is made up of cellulose plates, which are strong and often referred to as the "armor" of dinoflagellates.
- **Protein**: While proteins are present in various cellular structures, they do not constitute the theca of dinoflagellates.

5. **Conclusion:**
Based on the analysis, the correct answer is **C) Cellulose**.

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