A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap ?

Options

A. Acidic
B. Alkaline
C. Low refractive index
D. Absence of sugar

Answer

To determine which test result indicates that the collected sap is phloem sap, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Sap Composition**:
- Phloem sap is the fluid that transports nutrients, especially sugars, throughout the plant. It is different from xylem sap, which primarily carries water and minerals.

2. **Chemical Properties of Phloem Sap**:
- Phloem sap is generally alkaline, with a pH range of approximately 7.3 to 8.5. This means that if we test the sap and find it to be alkaline, it suggests that it is phloem sap.

3. **Analyzing the Options**:
- The options provided are:
1. Acidic
2. Alkaline
3. Low refractive index
4. Absence of sugar
- We need to identify which of these options aligns with the known properties of phloem sap.

4. **Evaluating Each Option**:
- **Option 1: Acidic** - This would indicate the sap is not phloem sap as phloem sap is alkaline.
- **Option 2: Alkaline** - This is consistent with the properties of phloem sap.
- **Option 3: Low refractive index** - This does not specifically indicate phloem sap.
- **Option 4: Absence of sugar** - Phloem sap typically contains sugars, so this would not indicate phloem sap.

5. **Conclusion**:
- Based on the analysis, the test result that indicates the collected sap is phloem sap is **Option 2: Alkaline**.

### Final Answer:
The test result that indicates the sap is phloem sap is **alkaline**.