Sclerenchyma tissue is made up of dead cells with thick walls that contain lignin and cellulose.

parenchyma cells are living cells. They are the main component of the soft tissues in plants, and are found in leaves, stems, roots, and fruits. 

Tracheid cells are specialized cells that dead at maturity and are responsible for transporting water and minerals from the roots to the rest of the plant. They are joined end-to-end to form a tube-like structure. 

Some parenchyma cells come from meristematic cells, but not all parenchyma cells are meristematic.