Lichens are composite organism made up of a fungus and a photosynthetic alga. Which of the following statements is wrong about lichen?

Options

A. Lichens are sensitive to air pollution because they have no way to excrete toxic substances
B. Algal partner (phycobiont) and fungal partner (mycobiont) live mutually
C. Algae prepare food for fungi and fungi provide shelter and absorb water + minerals for algal partner
D. None

Answer

To determine which statement about lichens is incorrect, we need to analyze the provided statements one by one. Lichens are composite organisms formed from a symbiotic relationship between a fungus and a photosynthetic alga. Here’s a step-by-step breakdown of the analysis:

### Step 1: Understand the Composition of Lichens
Lichens consist of two main components:
- **Fungal Partner (Mycobiont)**: This is usually an ascomycete or basidiomycete fungus.
- **Photosynthetic Partner (Photobiont)**: This is typically an alga (often from the Chlorophyta group) or a cyanobacterium.

### Step 2: Analyze Each Statement
1. **Statement 1**: "Lichens are sensitive to air pollution because they have no way to excrete toxic substances."
- This statement is **true**. Lichens are indeed sensitive to air pollution, especially sulfur dioxide (SO2), because they lack specialized structures to excrete toxins.

2. **Statement 2**: "The algal partner is called the photobiont and the fungal partner is called the mycobiont."
- This statement is **true**. The terminology used here is correct; the algal partner is referred to as the photobiont, and the fungal partner is the mycobiont.

3. **Statement 3**: "Algae prepare food for fungi, and fungi provide shelter and absorb water and minerals for the algal partner."
- This statement is **true**. In the symbiotic relationship, algae perform photosynthesis to produce food, while fungi provide protection and absorb water and minerals from the environment.

4. **Statement 4**: "None of the above statements are wrong."
- This statement suggests that all previous statements are correct.

### Step 3: Conclusion
Since all the statements regarding lichens are accurate, the correct answer to the question is:
- **Option 4: None of the above statements are wrong.**