Which one of the following can photosynthesise its food

Options

A. Hydra
B. Paramecium
C. Monocystis
D. Euglena.

Answer

To determine which organism can photosynthesize its food from the given options (Hydra, Paramecia, Monocystis, Euglena), we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding the Organisms**:
- We need to look at each organism and understand their classification and nutritional modes.

2. **Analyzing Hydra**:
- Hydra belongs to the phylum Cnidaria.
- It is known to be heterotrophic, meaning it cannot produce its own food and relies on consuming other organisms for nutrition.
- **Conclusion**: Hydra cannot photosynthesize.

3. **Analyzing Paramecium**:
- Paramecium is a unicellular protozoan.
- It does not possess photosynthetic pigments and is also heterotrophic.
- **Conclusion**: Paramecium cannot photosynthesize.

4. **Analyzing Monocystis**:
- Monocystis is a protozoan parasite that primarily resides in earthworms.
- As a parasite, it obtains its nutrients from its host and does not synthesize its own food.
- **Conclusion**: Monocystis cannot photosynthesize.

5. **Analyzing Euglena**:
- Euglena is a unicellular organism that can perform photosynthesis.
- It contains chloroplasts, allowing it to synthesize its own food through photosynthesis.
- Euglena can also exhibit heterotrophic behavior under certain conditions, but it is primarily known for its ability to photosynthesize.
- **Conclusion**: Euglena can photosynthesize.

6. **Final Answer**:
- After analyzing all options, the only organism that can photosynthesize its food is **Euglena**.