Processes Explained: The Movement of Water Through Plants

Water needs to travel up through the roots of a plant for photosynthesis in order for a plant to survive. Roots, like everything have cells, these are root hair cells. These root hair cells are long and a thin extension of the root epidermal cell. They only live for a few weeks before they die and are replaced by others growing near the tip. Because roots absorb water, minerals and ions they constantly loose water by transpiration so this needs to be replaced.
Every root hair cell is adapted to its function because:

• They have a large surface area because there's thousands of branches which come off of each root. 
• The root has a thin surface layer (made up of the cell membrane and the cellulose cell wall) which allows material to move across the plant easier. 

In damp conditions when there's more water, a solution forms which contains minerals and mostly water. 

In areas of high water potential in the soil means water moves by osmosis from the soil into the root hair. 

Once it's in the root hair cell it takes one of two paths - 

• the apoplastic pathway
• the symplastic pathway

To be continued...

This is based on AQA AS Biology Chapter 13 Movement of water through plants.