ME CLASSES ( BY Rahul Tripathi)
TISSUE
What are tissues
A group of cells similar in structure that work together to perform a particular function forms a
tissue.
All types of tissues have two basic components:
1. Cells: having common origin and function.
2. Inter-cellular substances: Are nonliving, fibrous, jelly-like substances.
Classification of tissues
Tissues are broadly classified as
1. Plant tissues.
2. Animal tissues
Plant Tissues
Plant tissues can be broadly divided into two main types. These are
1. Meristematic tissue
2. Permanent tissue.
Meristematic Tissues:
A meristematic tissue constitutes a group of actively dividing cells present in the growing
region of plant, e.g., the tips of roots and stems.
These tissues are responsible for increasing the length and girth of the plant.
The cells of tissue are compactly arranged and do not have intercellular space.
On the basis of their position in the plant body, meristematic tissues are classified into three types:
-
1. Apical
2. Lateral
3. Intercalary
Apical tissue:
These are present at the tips of roots, shoots, branches and leaves, which is called primary
growth.
Lateral tissue:
These are present along the lateral side of the stems and roots.
, It causes the organ (stem or root) to increase in diameter and girth. This is called secondary
growth.
Intercalary tissue :
They are located at the base of leaves or internodes, e.g., stems of grasses.
Functions of Meristematic tissue
Meristematic tissue acts as a parent tissue from which other tissues develop.
The place of injury in plants is healed up by the formation of new cells by meristems.
Permanent tissues:
A permanent tissue is a group of cells, which is derived from the meristematic tissues, but
these cells have lost the power of division temporarily or permanently.
Permanent tissues are of two types: -
1.simple permanent tissue
2.complex permanent tissue
Simple permanent tissues:
These tissues are composed of cells which are structurally and functionally similar. These tissues
are of three types:
1. parenchyma
2. collenchymas and
3. sclerenchyma
Parenchyma:
It consists of thin walled living cells.
The intercellular spaces are abundant.
The parenchyma is present in all the organs of the plants, i.e., roots, stems, leaves, flowers,
fruit and seeds.
TISSUE
What are tissues
A group of cells similar in structure that work together to perform a particular function forms a
tissue.
All types of tissues have two basic components:
1. Cells: having common origin and function.
2. Inter-cellular substances: Are nonliving, fibrous, jelly-like substances.
Classification of tissues
Tissues are broadly classified as
1. Plant tissues.
2. Animal tissues
Plant Tissues
Plant tissues can be broadly divided into two main types. These are
1. Meristematic tissue
2. Permanent tissue.
Meristematic Tissues:
A meristematic tissue constitutes a group of actively dividing cells present in the growing
region of plant, e.g., the tips of roots and stems.
These tissues are responsible for increasing the length and girth of the plant.
The cells of tissue are compactly arranged and do not have intercellular space.
On the basis of their position in the plant body, meristematic tissues are classified into three types:
-
1. Apical
2. Lateral
3. Intercalary
Apical tissue:
These are present at the tips of roots, shoots, branches and leaves, which is called primary
growth.
Lateral tissue:
These are present along the lateral side of the stems and roots.
, It causes the organ (stem or root) to increase in diameter and girth. This is called secondary
growth.
Intercalary tissue :
They are located at the base of leaves or internodes, e.g., stems of grasses.
Functions of Meristematic tissue
Meristematic tissue acts as a parent tissue from which other tissues develop.
The place of injury in plants is healed up by the formation of new cells by meristems.
Permanent tissues:
A permanent tissue is a group of cells, which is derived from the meristematic tissues, but
these cells have lost the power of division temporarily or permanently.
Permanent tissues are of two types: -
1.simple permanent tissue
2.complex permanent tissue
Simple permanent tissues:
These tissues are composed of cells which are structurally and functionally similar. These tissues
are of three types:
1. parenchyma
2. collenchymas and
3. sclerenchyma
Parenchyma:
It consists of thin walled living cells.
The intercellular spaces are abundant.
The parenchyma is present in all the organs of the plants, i.e., roots, stems, leaves, flowers,
fruit and seeds.
