Xylem and phloem structure (Other in-depth notes)

Xylem and phloem (Other in-depth notes)

Xylem

 - Transports water and soluble minerals UP the plant from the roots 

What is it composed of?  

> Vessels

> Fibres

> Parenchyma

> Tracheid  (Yes, that’s the spelling)

> 1 - Vessels 

•  It has lignin walls, which means they are dead.  Hence, they have no contents inside
•  They are linked end-to-end which creates a continuous column with proliferation plates
•  Contains pits/pores

> 2 - Tracheids

•  These also contain lignin.  They are not found in the same plant as xylem vessels.  Xylem vessels are fatter and shorter.
•  Linked end-to-end
•  Sloped ends with pores/pits in them

> 3 - Fibres

 - The walls have lignin in 

 - Do not transport water and run along side the xylem vessel

 - It’s function is to act as support

> 4 - Parenchyma 

•  They are actually living!  
•  Provide turgidity, which is basically providing support
•  Stores starch and minerals

So, some general points on structure - 

 - Continuous…