2. Tissues that have the ability to enlarge, stretch and differentiate into other
types of cells as they mature. The cells of this tissue are generally young and
immature, with the power of continuous division.
Meristematic cells are all living cells. The meristematic cells can be oval or
rounded or polygonal in shape. They have a large nucleus with no vacuoles.
Intercellular space between cells is absent. The cells are also small in size but
have a high capacity of cell division.
3.
4. ON THE BASIS OF ORIGIN:
Meristems are 3 types:
PROMERISTEM: Also know as embryonic meristem. Present at the apices of the shoot and
root tip. It divides to form primary meristem.
PRIMARY MERISTEM: Found below the pro-meristem in the shoot and root tip. They divide
to produce primary permanent tissue that forms the primary plant body.
SECONDARY MERISTEM: It is formed later in the plant body. It develops from primary
permanent tissue due to dedifferentiation. They divide to produce secondary permanent
tissue that forms the secondary plant body. They are interfascicular cambium & cork
cambium.
8. ON THE BASIS OF POSITION:
Meristems are 3 types:
APICAL MERISTEM: These meristems are located on the tip of the root, stem etc. They help in the growth of
the root system as well as the shoot system. The various cell divisions along with the cellular enlargement help
in the growth of the stem above the ground and the growth of the root below the ground.
9. INTERCALARY MERISTEM:The intercalary meristems are located at the internodes or the base of the leaves. The
intercalary meristems help in increasing the length of the internode. This is usually seen in monocotyledonous plants.
10. LATERAL MERISTEM: The lateral meristems are present on the lateral side of the stem and root of a plant. These meristems
help in increasing the thickness of the plants. The vascular cambium and the cork cambium are good examples of a lateral
meristematic tissue..
Intrafascicular cambium is present in primary plant body but divides to produce secondary permanent tissue.
11. ON THE BASIS OF FUNCTION:
Meristems are 3 types:
PROTODERM: Forms the Epidermal tissue system.
PROCAMBIUM: Forms the Vascular tissue system.
GROUND MERISTEM: Forms the Fundamental or Ground tissue system.
ON THE BASIS OF PLANE OF DIVISION:
Meristems are 3 types:
RIB MERISTEM: Cells divide in one plane, forming a row of cells. E.g., formation of lateral roots.
PLATE MERISTEM: Cells divide in two planes, forming a plate like structure. E.g., formation of lamina in leaves.
MASS MERISTEM: Cells divide in all planes, forming a mass of cells. E.g., formation of cortex, pith, endosperm.
