explain--growth in plants is largely restricted to specialized regions of active cell division called meristems
Answers
A meristem is alocalised region in which actual cell division occurs.
The growth in plants is restricted to specialized regions called meristem because meristem has a capability to divide throughout life .
Explanation:
Meristematic tissue
They are formed of cells that have ability to divide continuously throughout their life and help in increasing the length and girth of the plant.
Characteristics of meristematic cells
They have thin cellulose cell walls.
o The meristematic cells may be spherical, oval, polygonal or rectangular in shape. The meristematic cells are compactly arranged.
o Each meristematic cell contains dense or abundant cytoplasm and a single large nucleus.
o The meristematic cells contain few vacuoles or no vacuoles at all.
Occurrence
According to their position in the plant, meristems are of three types:
o Apical meristem
o Lateral meristem
o Intercalary meristem
Apical meristems
It is present at growing tip of stems and roots. It is at shoot apex and root apex.
Its function is to increase the height of the plant.
Lateral meristems
These are found beneath the bark (called cork cambium).
Its function is to help in increase in diameter
Intercalary meristems
It is located at the base of leaves or at internodes.
Its function is to increase number of branches.