Which one of the following is a saprophytic protist

Options

A. Desmid
B. Nostoc
C. Slime Mould
D. Gonyaulax.

Answer

To determine which of the given options is a saprophytic protist, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Term "Saprophytic":**
- Saprophytic organisms are those that feed on dead and decaying organic matter. They play a crucial role in the ecosystem by decomposing organic materials.

2. **Identify the Characteristics of Protists:**
- Protists are unicellular eukaryotes that can have various modes of nutrition, including autotrophic (self-feeding through photosynthesis) and heterotrophic (feeding on other organisms or organic matter).

3. **Examine the Given Options:**
- The options provided are:
1. Desmid
2. Nostoc
3. Slime molds
4. Gorniolax

4. **Analyze Each Option:**
- **Desmid:** This is a type of green algae that contains chlorophyll and can perform photosynthesis. Therefore, it is autotrophic and not saprophytic.
- **Nostoc:** This is a cyanobacterium that also performs photosynthesis, making it autotrophic. Thus, it is not the correct answer.
- **Slime Molds:** These are protists that exhibit a saprophytic mode of nutrition. They thrive on decaying organic matter, such as dead leaves and twigs, breaking them down and recycling nutrients.
- **Gorniolax:** This is a type of dinoflagellate that can perform photosynthesis, indicating it is autotrophic and not saprophytic.

5. **Conclusion:**
- Based on the analysis, the only option that fits the definition of a saprophytic protist is **slime molds**.

### Final Answer:
The saprophytic protist among the options is **slime molds**.

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