Which of the following organisms is an odd one out with respect to mode of nutrition?

Options

A. Gonyaulax
B. Chlamydomonas
C. Trypanosmona
D. Nostoc

Answer

To solve the question of which organism is the odd one out with respect to mode of nutrition, we will analyze the nutritional modes of each of the given organisms.

### Step-by-Step Solution:

1. **Identify the Organisms:**
- The organisms listed are Goniolax, Chlamydomonas, Trypanosoma, and Nostoc.

2. **Determine the Mode of Nutrition for Each Organism:**
- **Goniolax:** This is a type of dinoflagellate, which is a group of algae. They are photoautotrophic, meaning they can produce their own food using light.
- **Chlamydomonas:** This is also a type of green algae. Like Goniolax, Chlamydomonas is autotrophic and can synthesize its own food through photosynthesis.
- **Trypanosoma:** This is a parasitic protozoan. Unlike the previous two, Trypanosoma is heterotrophic, meaning it cannot produce its own food and relies on a host organism for nutrition.
- **Nostoc:** This is a type of cyanobacteria (often referred to as blue-green algae). Nostoc is also autotrophic, capable of photosynthesis and producing its own food.

3. **Compare the Modes of Nutrition:**
- Goniolax, Chlamydomonas, and Nostoc are all autotrophs (they can make their own food).
- Trypanosoma is the only heterotroph (it cannot make its own food and depends on a host).

4. **Identify the Odd One Out:**
- Since Trypanosoma is the only organism that does not have the ability to produce its own food, it is the odd one out in this group.

### Conclusion:
The organism that is the odd one out with respect to mode of nutrition is **Trypanosoma**.

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