TISSUES

TISSUES : 

TISSUES

Tissues: : 

Tissues: A tissue may be defined as a group or collection of similar or dissimilar cells that perform or help a common function and have a common origin.

Organization Of Tissues: : 

Organization Of Tissues:

Plant Tissues: : 

Plant tissue can be classified as follows : Plant Tissues:

Meristematic Tissues:1 : 

The cells of meristematic tissues are similar in structure and have thin and elastic primary cell walls made up of cellulose. The meristematic cells may be rounded, oval, polygonal or rectangular in shape. They are compactly arranged without any intercellular space between them. Each cell contains dense or abundant cytoplasm and a large prominent nucleus. They have few small or no vacuoles at all. Meristematic Tissues:1

Meristematic Tissues:2 : 

Occurrence: The meristematic cells are restricted to certain specific regions which continuously add new cells to the plant body. Meristematic Tissues:2

Meristematic Tissues:3 : 

Depending upon the occurrence and position in the plant body, meristems are divided into: Apical meristem Lateral meristem Intercalary meristem Meristematic Tissues:3

Apical Meristem: : 

Occurrence: This meristem is located at the growing apices of main and lateral shoots and roots. Functions: These cells are responsible for linear growth of an organ. Examples – root apical meristem and shoot apical meristem. Apical Meristem:

Lateral Meristem: : 

Occurrence: Lateral meristem usually occurs beneath the bark in the form of cork cambium and in vascular bundles of dicots in the form of vascular cambium. Functions: This meristem consists of initials which divide mainly in one plane and cause the organ to increase in diameter and in girth Lateral Meristem:

Intercalary Meristem: : 

Occurrence: This meristem is located at the base of leaves or internodes (on either side of the node ) on twigs. It is usually found in monocot plants. Functions: It increases the length between the two nodes.. Intercalary Meristem:

Permanent Tissues:1 : 

Permanent tissues originate from meristematic tissues and become permanent at fixed positions in the plant body. They are made up of mature cells that have lost their power of division. They have definite shape, size and function. They may be living or dead. The living permanent cells are large and usually possess thin walls enclosing vacuolated cytoplasm. The dead permanent cells are usually thick walled without cytoplasm. Permanent Tissues:1

Permanent Tissue:2 : 

Permanent Tissue:2

Simple Permanent Tissue: : 

Simple Permanent Tissue: