A . Much of nitrogen in xylem sap is carried in organic form.
B. In phloem , movement of nutrients is always unidirectional .

Options

A. Only A is correct
B. Only B is correct
C. Both A & B are correct
D. Both A & B are incorrect

Answer

### Step-by-Step Solution:

1. **Understanding the Role of Xylem and Phloem**:
- Xylem is responsible for transporting water and dissolved minerals from the roots to the rest of the plant.
- Phloem is responsible for transporting the products of photosynthesis (mainly sugars) from the leaves to other parts of the plant.

2. **Analyzing Statement A**:
- The statement claims that much of the nitrogen in xylem sap is carried in organic form.
- Nitrogen is primarily absorbed by plants in the form of nitrates (NO3-) and ammonium (NH4+), which are inorganic forms.
- However, once absorbed, nitrogen can be converted into organic compounds (like amino acids) and transported in the xylem.
- Therefore, this statement is **true**.

3. **Analyzing Statement B**:
- The statement claims that in phloem, the movement of nutrients is always unidirectional.
- In reality, phloem transport is bidirectional. Nutrients (sugars) produced in the leaves can move both upward to the growing tips and downward to the roots.
- Therefore, this statement is **false**.

4. **Conclusion**:
- Statement A is true: Much of the nitrogen in xylem sap is carried in organic form.
- Statement B is false: In phloem, movement of nutrients is not always unidirectional; it is bidirectional.
- Thus, only statement A is correct.