Select the incorrect statement.

Options

A. Photosynthesis takes place in the leaf of a plant.
B. Relation between fungi and roots of higher plants is parasitic in nature.
C. Rhizobium often lives in the roots of pea and bean plants.
D. Cuscuta is a total parasitic plant that has no leaves and roots.

Explanation

To solve the question of selecting the incorrect statement, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Analyze Statement A: "Photosynthesis takes place in the leaf of a plant."**
- Photosynthesis is the process by which plants convert sunlight into energy, primarily occurring in the leaves where chlorophyll is present.
- **Conclusion:** This statement is correct.

2. **Analyze Statement B: "Relations between fungi and roots of higher plants is parasitic in nature."**
- The relationship between fungi and the roots of higher plants, such as mycorrhizae, is typically mutualistic, meaning both organisms benefit from the relationship.
- **Conclusion:** This statement is incorrect because it describes a mutualistic relationship as parasitic.

3. **Analyze Statement C: "Rhizobium often lives in the roots of pea and bean plants."**
- Rhizobium is a type of bacteria that forms a symbiotic relationship with legumes like peas and beans, helping them fix nitrogen from the atmosphere.
- **Conclusion:** This statement is correct.

4. **Analyze Statement D: "Cascota is a parasitic plant that has no leaves and roots."**
- Cascota (Cuscuta) is indeed a parasitic plant that attaches to host plants and lacks chlorophyll, thus does not have leaves or roots of its own.
- **Conclusion:** This statement is correct.

### Final Conclusion:
After analyzing all the statements, we find that the incorrect statement is **B: "Relations between fungi and roots of higher plants is parasitic in nature."** This statement mischaracterizes the relationship as parasitic instead of mutualistic.

### Answer:
**B** is the incorrect statement.

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