Read the following statements carefully and identify correct statements w.r.t. Lichens
a. The association cannot tolerate air pollution, especially due to sulphur dioxide
b. Lichens are annuals and their growth is slow
c. The fungal partner mostly belongs to ascomycetes.
d. Soredia are most efficient means of asexual reproduction
e. Orchids seldom occur without this association
f. Foliose lichens are pioneers of succession in a water body.

Options

A. c,d,f
B. a,c,d,f
C. a,b,e
D. a,c,d

Answer

To solve the question regarding the correct statements about lichens, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement a**: "The association cannot tolerate air pollution, especially due to sulphur dioxide."
- **Analysis**: This statement is **correct**. Lichens are sensitive to air pollution, particularly sulphur dioxide, which can harm the symbiotic relationship between the fungal and algal partners.

2. **Statement b**: "Lichens are annuals and their growth is slow."
- **Analysis**: This statement is **incorrect**. Lichens are non-flowering organisms and do not fit the definition of annuals. While their growth can be slow under unfavorable conditions, they can grow rapidly when conditions are suitable.

3. **Statement c**: "The fungal partner mostly belongs to ascomycetes."
- **Analysis**: This statement is **correct**. The majority of fungal partners in lichens are indeed from the Ascomycetes group.

4. **Statement d**: "Soredia are the most efficient means of asexual reproduction."
- **Analysis**: This statement is **correct**. Soredia are small, powdery propagules that facilitate asexual reproduction in lichens, making this statement true.

5. **Statement e**: "Orchids seldom occur without this association."
- **Analysis**: This statement is **incorrect**. While some orchids have symbiotic relationships with fungi (mycorrhizae), they do not rely on lichens specifically for their growth.

6. **Statement f**: "Foliose lichens are pioneers of succession in a water body."
- **Analysis**: This statement is **incorrect**. Foliose lichens are not typically considered pioneers in aquatic succession; they are more commonly found in terrestrial environments.

### Conclusion:
The correct statements regarding lichens are:
- a. The association cannot tolerate air pollution, especially due to sulphur dioxide.
- c. The fungal partner mostly belongs to ascomycetes.
- d. Soredia are the most efficient means of asexual reproduction.

Thus, the correct answers are **a, c, and d**.

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