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.
Why are most cells undergoing mitosis in the root tip? There is the meristem. It's logical that's more conveniant for a plant to grow at the tip of the root than at the beginning of it and then move the whole root forward.