Question

Why was it necessary to take coloured eosin solution in water in the beaker to show that water is conducted upwards through xylem

Answer 1

The experiment indicates clearly that the red-coloured eosin solution has been absorbed by the root system and trans located up-ward through stems and leaves. This is a case of passive absorption which depends upon transpiration pull. We take colored eosin solution to check movement of water in stem through xylem.