Identify the correct pair of characters of a bacterium which is useful in production of methane
(i) Recyclers of inorganic nutrients (ii) Present in stomach of cattle (iii) Obtain energy from sunlight (iv) Aerobes

Options

A. ii, iii
B. i, ii
C. i, iv
D. iii, iv

Answer

To solve the question about identifying the correct pair of characters of a bacterium that is useful in the production of methane, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of Methanogens**:
- Methanogens are a type of bacteria that produce methane (CH4) as a byproduct of their metabolic processes. They are primarily involved in anaerobic respiration, where they convert carbon dioxide and hydrogen into methane and water.

2. **Analyze Each Option**:
- **Option (i)**: Recyclers of inorganic nutrients.
- Methanogens do recycle inorganic nutrients as they utilize carbon, hydrogen, and other inorganic elements in their metabolic processes. This option is correct.

- **Option (ii)**: Present in the stomach of cattle.
- Methanogens are indeed found in the digestive systems of ruminants, such as cows and buffaloes. They help in breaking down food and producing methane in the process. This option is also correct.

- **Option (iii)**: Obtain energy from sunlight.
- This statement is incorrect. Methanogens do not obtain energy from sunlight; they are not photosynthetic. Instead, they derive energy from chemical reactions involving inorganic compounds.

- **Option (iv)**: Aerobes.
- This option is incorrect as well. Methanogens are anaerobic bacteria, meaning they thrive in environments without oxygen. Aerobes require oxygen for their metabolic processes and do not produce methane.

3. **Conclusion**:
- The correct pair of characters for a bacterium useful in the production of methane is:
- (i) Recyclers of inorganic nutrients
- (ii) Present in stomach of cattle

### Final Answer:
The correct options are (i) and (ii).

---