Homeostasis: how water/minerals are transported in plants (xylem)

Question 1

Why/how does the xylem transport water and minerals (in detail)

Answer 1

The root cells contain a higher concentration of dissolved nutrients than the surrounding soil, so water moves into the roots by osmosis. minerals usually move across cell membranes through active transport. 90% or more of the water that reaches the leaf is lost to the atmosphere when it evaporates through the stomata. this process of water loss from a plant is called transpiration. there are two processes that move the water from the roots to leave, being root pressure and transpirational pull

Question 2

What is root pressure

Answer 2

responsible for positive pressure. water entering the roots creates a positive pressure that tends to push water upwards. this process is aided by the adhesion (sticking) of water molecules to the cell walls of the xylem tissue

Question 3

What is transpirational pull

Answer 3

the transpiration (evaporation) of water from the leaves of a plant creates a negative pressure that acts to pull water up to replace the lost water. the columns of water in the xylem have a property called cohesion. the force of attraction between the water molecules in each narrow xylem tube provides a force that keeps the water column unbroken while its being pulled up under tension. this process is aided by the adhesion (sticking) of water molecules to the cell walls of the xylem tissue. Dry air, heat, and wind increase transpirational pull