Which of the following theories is primarily proposed to explain the upward movement of water from roots to the shoot?

Guttation is caused by which of the following?

In the elements of xylem,water rises to a certain height in the xylem vessels. Which pressure force in the xylem is useful for maintaining metabolic activities?

The ascent of xylem sap in plants is mainly accomplished by the :

When the cut stump of a plant is fitted with a manometer,the level of mercury rises due to the accumulation of:

Which of the following are objections to the root pressure theory of ascent of sap in plants?
$I$. It is not applicable to plants taller than $20 \ m$.
$II$. Ascent of sap occurs even in the absence of a root system.
$III$. Root pressure is almost zero in tall gymnosperms.
$IV$. Root pressure is the only mechanism explaining the ascent of sap.
$V$. Root pressure is not developed in actively transpiring plants.