 Xylem – brings water from the root to the leaves of the plants  Phloem – transports sugar from one part of the plant to another

 Water – taken up by root hairs  From root hairs – towards the center  Here it enters the xylem  Xylem -> root -> stem -> leaf  Transpiration - water evaporates from plant cells and diffuses into air via leaf

 In a leaf – water evaporates from wet cell walls  Air space inside leaf full of water vapor  High concentration of water vapor inside leaf than outside  Water diffuses from inside to outside through stomata into air  This is traspiration

 Root hairs grow down  New root hairs grow behind the old ones Die  Lasts for less than a day  Grow between soil particles  Water enters via osmosis  Increases surface area to speed up osmosis

Root hair cross section How water travels into the root: passes through the cortex No chloroplast in cortex cells Moves towards the center of the root Some goes into cytoplasm of cells, through the cells and into the next cell till it reaches the xylem Most goes in between cells or though cell walls and never actually into cells.

 Made of long hollow dead cells placed end to end to form a continuous tube  Water enters through tiny holes in the xylem called pits

 Water leaves xylem vessels and some enters the mesophyll cells  Water evaporates into air space as water vapor (cuticle prevents too much water loss)  Water diffuses out of stomata into air  Air takes away water vapor

Type of cellsFunctionPicture Root Hair cells: Found on outside of plant roots/ above root tip Long/ thin reaching out into soil Help anchor the plant to the soil Absorb water mineral ions from soil Has large surface area so that lots of dissolved nutrients can get inside the cell quickly Xylem Cell: Empty / dead cell Cell wall fill with lignin – hardens / strong / waterproof / with cellulose 1 cell = xylem vessel element – no end walls end to end formation – forming long continuous tubing from roots to leaves (1) transport water / minerals from root to parts of plant (2) structural support to plant (lignin)

Place in pathwayHow water travels Root hairBy osmosis water enters root hairs. From here water passes into the root cortex Root cortexWater moves more in between cells than through cells into the center towards the xylem xylemIn the xylem, water moves up the xylem due to the water potential gradient between the water and air. Water potential in air is less than water potential in roots and therefore the water moves up the stem Mesophyll cellsWater moves down the water potential gradient from the xylem vessel and into the cell walls of the mesophyll. This reduces the pressure at the top off the xylem vessel. The difference in pressure causes water to move up the xylem (root to the top) Water produces tension / cohesive (water molecules stick to each other) Properties that allow water to flow upwards.

 The cytoplasm of root cells usually have much higher total solute concentrations than water in the surrounding soil.  Thus, water diffuses into root cells by osmosis.  Water must cross the cortex of the root to enter the xylem.  water moves by capillary action through cortex cell walls until it reaches the endodermis.  90 % of water moves through the route this way.