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?

1.  Acidic

2.  Alkaline

3.  Low refractive index

4.  The absence of sugar

Root pressure develops due to?
1. Active absorption
2. Low osmotic potential in Soil
3. Passive absorption
4. Increase in transpiration