Water transport in vascular plants

Question 1

Root Pressure

Answer 1

-water + inorganic nutrients in soil are transported upwards in the xylem
-osmosis and diffusion draw water into root hairs and xylem of roots
-results in positive pressure that pushes sap a short distance up xylem to leaves

Question 2

Capillary Action

Answer 2

-liquid in narrow spaces flow upward
-adhesion forces take over when water molecules have weak electric charges and cling to walls of xylem tubes
-cohesion forces occur between the electrically charged water molecules causing a long unbroken column of water to form inside the xylem
(molecules stick together
-forces create surface tension

Question 3

Transitional Pull

Answer 3

-transition takes place in the leaves – -evaporation causes water to escape into atmosphere through stomata
-water is pulled between microfibrils of mesophyll cell walls and crescent shape menessics are formed
-more curve=more surface tension which creates negative pressure that pulls water out of cell and out of xylem
-transportational pull is then created and provides all energy for evaporation
-powered by sun