Phototrophs and chemotrophs are defined on the basis of their

Options

A. energy source
B. requirement of organic and inorganic substances
C. metabollsm
D. Structure

Answer

**Step-by-Step Solution:**

1. **Understanding the Definitions**:
- Phototrophs are organisms that obtain energy from light (sunlight).
- Chemotrophs are organisms that obtain energy from chemical compounds.

2. **Energy Source**:
- The primary distinction between phototrophs and chemotrophs lies in their energy source.
- Phototrophs utilize light energy, while chemotrophs rely on chemical energy from organic or inorganic substances.

3. **Nutritional Requirements**:
- Phototrophs can be further classified into autotrophs (which can produce their own food using light) and heterotrophs (which cannot and must consume other organisms).
- Chemotrophs can also be autotrophic or heterotrophic, depending on whether they can synthesize their own food or not.

4. **Metabolism**:
- The metabolic processes of phototrophs involve photosynthesis, where light energy is converted into chemical energy.
- Chemotrophs undergo chemosynthesis or respiration, where chemical reactions break down substances to release energy.

5. **Conclusion**:
- In summary, phototrophs and chemotrophs are defined based on their energy sources: light for phototrophs and chemical compounds for chemotrophs.