1 Tuberculous pleuritis may occur in some people who have the lung disease from tuberculosis.  The pleural disease occurs from the rupture of a diseased area into the pleural space, the space between the lung and the lining of the chest and abdominal cavities.
The root apical meristem is a region of growth tissue near the tip of each root. The meristematic cells in this region grow in two directions, both backward toward the above-ground shoot and forward toward the tip of the root.
On the basis of origin and development of initiating cells, meristems can be divided into three types: (i) Promeristem or priordial meristem: A group of young meristematic cells of a growing organ. It is the early embryonic meristem from which other advanced meristems are derived. In a plant, it occupies a small area at the tip of stem and root. It further divides to form primary meristem. (ii) Primary meristem: These are derived from promeristem. They are present below the promeristem at shoot and root apices. These cells divide and form permanent tissues. (iii) Secondary meristem: