How many of the following statements are incorrect ?
(i) Decomposition is largely an anaerobic process .
(ii) Fragmentation , leaching , and catabolism occur simultaneously on detritus.
(iii) The vertical distribution of different species occupying different levels is called stratification .
(iv) The pond is a deep water body .
(v) The rate of decomposition is controlled by the chemical composition of detritus and climatic factors.

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine how many of the given statements are incorrect, let's analyze each statement one by one:

1. **Statement (i)**: "Decomposition is largely an anaerobic process."
- **Analysis**: This statement is incorrect. Decomposition primarily occurs through aerobic processes, where oxygen is present. Anaerobic decomposition does occur, but it is not the dominant form in most ecosystems.

2. **Statement (ii)**: "Fragmentation, leaching, and catabolism occur simultaneously on detritus."
- **Analysis**: This statement is correct. Fragmentation (breaking down of organic matter), leaching (the process of nutrients being washed away), and catabolism (the breakdown of complex molecules into simpler ones) can occur simultaneously on detritus.

3. **Statement (iii)**: "The vertical distribution of different species occupying different levels is called stratification."
- **Analysis**: This statement is correct. Stratification refers to the layering of different species in an ecosystem, particularly in aquatic environments where different species occupy different depths.

4. **Statement (iv)**: "The pond is a deep water body."
- **Analysis**: This statement is incorrect. Ponds are typically shallow water bodies that support rooted plants. They are not classified as deep water bodies.

5. **Statement (v)**: "The rate of decomposition is controlled by the chemical composition of detritus and climatic factors."
- **Analysis**: This statement is correct. The rate of decomposition is influenced by various factors, including the chemical composition of the organic matter and environmental conditions such as temperature and moisture.

Now, let's summarize the findings:

- Incorrect Statements: (i) and (iv)
- Correct Statements: (ii), (iii), and (v)

**Conclusion**: There are 2 incorrect statements.

### Final Answer:
**2 incorrect statements.**

---