Select the incorrect from the following.

Options

A. Diatomaceous earth ' is from by the cell wall of diatoms.
B. Viriods consists of protein coat .
C. Phycomycetes are also called algal fungi .
D. Golden algae are also called desmids .

Answer

To solve the question, we need to analyze each of the given statements and determine which one is incorrect.

1. **Diatomaceous earth is formed by the cell wall of diatoms.**
- This statement is correct. Diatomaceous earth is indeed formed from the fossilized remains of diatoms, which have silica-rich cell walls.

2. **Viroids consist of protein coat.**
- This statement is incorrect. Viroids are small infectious agents that consist solely of a short circular RNA and do not have a protein coat. Therefore, this statement is false.

3. **Phycomycetes are also called algal fungi.**
- This statement is correct. Phycomycetes, or water molds, have characteristics similar to algae, which is why they are sometimes referred to as algal fungi.

4. **Golden algae are also called desmids.**
- This statement is correct. Golden algae, which belong to the group Dinoflagellates, are sometimes referred to as desmids, although the term is more commonly associated with a specific group of green algae.

Based on the analysis, the incorrect statement is:

**Viroids consist of protein coat.**

### Step-by-Step Solution:
1. **Identify the statements provided in the question.**
- Diatomaceous earth is formed by the cell wall of diatoms.
- Viroids consist of protein coat.
- Phycomycetes are also called algal fungi.
- Golden algae are also called desmids.

2. **Evaluate each statement for accuracy.**
- The first statement is correct.
- The second statement is incorrect (viroids do not have a protein coat).
- The third statement is correct.
- The fourth statement is correct.

3. **Determine which statement is incorrect.**
- The only incorrect statement is "Viroids consist of protein coat."

4. **Conclude the answer.**
- The incorrect option is: **Viroids consist of protein coat.**