Which of the following are likely to be present in deep sea water ?

Options

A. Saprophytic fungi
B. Archaebacteria
C. Eubacteria
D. Blue-green algae

Answer

To determine which organisms are likely to be present in deep sea water, we can analyze the options provided: Saprophytic fungi, archaebacteria, eubacteria, and blue-green algae.

### Step-by-Step Solution:

1. **Understanding Deep Sea Conditions**:
- Deep sea environments are characterized by extreme conditions such as high pressure, low temperature, and low light availability. Organisms that thrive in these conditions are often specially adapted.

2. **Analyzing the Options**:
- **Saprophytic Fungi**: These organisms decompose dead organic matter and are typically found in terrestrial environments rather than deep sea conditions.
- **Archaebacteria**: This group of microorganisms is known for thriving in extreme environments. They can be divided into categories such as Halophiles (salt-loving), Methanogens (methane-producing), and Thermoacidophiles (heat and acid-loving). Some archaebacteria can survive in extreme depths of the ocean, making them a strong candidate.
- **Eubacteria**: While some eubacteria can survive in various environments, they are not specifically adapted to the extreme conditions of deep sea water compared to archaebacteria.
- **Blue-Green Algae**: Also known as cyanobacteria, these organisms require light for photosynthesis and are typically found in shallow waters where sunlight can penetrate. They are less likely to be present in the deep sea.

3. **Conclusion**:
- Based on the analysis, the organism most likely to be present in deep sea water is **Archaebacteria**. Their unique adaptations allow them to survive in the extreme conditions found in deep ocean environments.

### Final Answer:
**B. Archaebacteria**

---