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 determine the odd one out with respect to mode of nutrition among the given organisms, we will analyze each organism's nutritional mode:

1. **Goniolax**: This organism is a phototroph, meaning it can convert light energy into chemical energy through photosynthesis. It is classified as an autotroph because it produces its own food.

2. **Chlamydomonas**: Similar to Goniolax, Chlamydomonas is also a photosynthetic organism. It is an alga that can synthesize its own food using sunlight, thus it is also an autotroph.

3. **Trypanosoma**: This organism is a parasitic protozoan. It does not produce its own food; instead, it derives nutrients from its host. This mode of nutrition is known as heterotrophic nutrition.

4. **Nostoc**: Nostoc is another autotrophic organism. It contains chlorophyll and can perform photosynthesis to produce its own food. Additionally, it has the ability to fix atmospheric nitrogen, which is beneficial for plants.

Now, comparing the modes of nutrition:
- Goniolax, Chlamydomonas, and Nostoc are all autotrophs, meaning they can produce their own food through photosynthesis.
- Trypanosoma, on the other hand, is a heterotroph, meaning it relies on other organisms (its host) for nutrition.

**Conclusion**: The odd one out is **Trypanosoma** because it follows a heterotrophic mode of nutrition, while the others are autotrophs.