Transport in Plants Test - 5

The fungus provides minerals and water to the roots, inturn the roots provide sugars and N-containing compounds to themycorrhizae. Some plants have an obligate association with themycorrhizae.

The process of movement of water and minerals from roots to leaves in plant through xylem tissues is called ascent of sap. The most accepted theory of ascent of sap is cohesion-tension theory.

The excess water collects in the form of droplets around special openings of veins near the tip of grass blades, and leaves of many herbaceous parts. Such water loss in its liquid phaseis known as guttation.

Neighbouring cells are connected through cytoplasmic strands that extend through plasmodesmata. During symplastic movement, the water travels through the cells – their cytoplasm; intercellular movement is through the plasmodesmata.

Translocation is a biological process that occurs in all plants and involves the movement of water and other soluble nutrients through the xylem and phloem from one part of the plant to another.

A cell dipped in 0.5 M sucrose has no effect due to osmosis as concentration of sucrose is more of equal to cytoplasm but 0.5 M NaCl cause exosmosis that leads to plasmolysis.

Cohesion and adhesion between wall of tracheid and water molecule prevent rupture and fractionalization of water column present in treachery elements during ascent of sap.

The apoplastis the system of adjacent cell walls that iscontinuousthroughout the plant, except at the casparianstrips of the endodermis in the roots. The apoplastic movement of water occurs exclusively through the intercellular spaces and the walls of the cells.

Bulk flow can be achieved either through a positive hydrostatic pressure gradient (e.g., a garden hose) or a negative hydrostatic pressure gradient (e.g., suction through a straw).

During symplastic movement, the watertravels through the cells – their cytoplasm; intercellular movement isthrough the plasmodesmata. Water has to enter the cells through the cell membrane; hence the movement is relatively slower.