which of the following statement is incorrect w.r.t. Azolla? (a) it is an aquatic water fern (b) it is used as biofertilizer (c) it is homosporous vascular cryptogam (d) it shows symbiotic association with alga Anabaena which fixes atmospheric nitrogen

Options

A. all except (c)
B. (a) & (b)
C. (c) only
D. (d) only

Answer

To determine which statement about Azolla is incorrect, let's analyze each option step by step:

1. **Statement (a): It is an aquatic water fern.**
- Azolla is indeed an aquatic fern that floats on water surfaces. It belongs to the family of ferns and is commonly found in freshwater habitats. Therefore, this statement is **correct**.

2. **Statement (b): It is used as a biofertilizer.**
- Azolla is known for its ability to fix atmospheric nitrogen due to its symbiotic relationship with the cyanobacterium Anabaena. This property makes it an effective biofertilizer, especially in rice paddies. Thus, this statement is also **correct**.

3. **Statement (c): It is homosporous vascular cryptogam.**
- Azolla is not homosporous; it is actually heterosporous, meaning it produces two different types of spores: microspores and megaspores. Therefore, this statement is **incorrect**.

4. **Statement (d): It shows symbiotic association with alga Anabaena which fixes atmospheric nitrogen.**
- This statement is true. Azolla has a symbiotic relationship with the cyanobacterium Anabaena, which is responsible for nitrogen fixation. Hence, this statement is **correct**.

Based on the analysis above, the incorrect statement regarding Azolla is **(c) it is homosporous vascular cryptogam**.

### Final Answer:
The incorrect statement is **(c) it is homosporous vascular cryptogam**.