Question

First theory for ascent of sap was proposed by

• A. Westermeier
• B. Godlewski
• C. Bose
• D. Stephen Hales

Answer 1

The correct option is B Godlewski

The first theories proposed to explain ascent of sap were Vital force theories. These theories believed that living cells are involved in the ascent of sap, e.g., relay pump theory by Godlewski, 1883 and Pulsation theory by Bose, 1923.

Bose believed that the inner most cortical cells pump water into the interior that contains xylem channels. The vital force theories have been discarded because as proved by Boucherie in 1840 and Strasburger in 1891 water rises up the stem even when all the living cells are killed by poison or heat.