GENERAL BILOGY 1 - BIOLOGY PLANTS TISSUE PORTABLE DOCUMENT FORMAT.pdf

Plant tissue refers to groups of similar plant cells that work together to perform specific functions in plants. Plant tissues are broadly categorized into meristematic and permanent tissues.

1. Name – Shreyas P
Class - 9
Subject - Biology
Topic - Tissues[ Plant tissues ]

2. Plant Tissues
Plant tissue - Plant tissues 
are of two main
types meristematic and permanent.
Meristematic
 
tissue 
is the dividing 
tissue 
present in the
growing regions of the
 
plant. Permanent
 
tissues 
are
derived from meristematic
 
tissue 
once they lose the
ability to divide.

3. Meristematic tissue
The meristem is a type of tissue found in plants. It
consists of undifferentiated cells capable of cell
division. Cells in the meristem can develop into all
the other tissues and organs that occur in plants.
These cells continue to divide until a time when they
get differentiated and then lose the ability to divide.
 

4. Three type of Meristematic
tissue
1)Apical meristems -These
 
meristems 
are located on
the tip of the root, stem etc.
2)Intercalary meristem - The
 
intercalary
meristems 
help in increasing the length of the
internode.
3) Lateral Meristems - The
 
lateral meristems 
are
present on the
 
lateral  
side of the stem and root of a
plant.

5. Permanent Tissues
Permanent tissues 
in a plant are those 
tissues 
that
contain non dividing cells. The cells are also modified
to perform specific functions in the plants. The cells of
the
 
permanent tissue 
are derived from the
meristematic
 
tissue.

6. Two types of Parmanent Tissue
1]Simple Permanent Tissues .
2]Complex Permanent Tissue.
Simple Permanent Tissues
These tissues are simple. They are made up of only one
 
type of cell. Here, all the cells that make up the tissue are
similar and have the same structure, with the same type
parts. Simple permanent tissues are again classified into
three main types. They are parenchyma, collenchyma,
and sclerenchyma.

7. Parenchyma – The cells of this tissue are living, with thin
cell walls. Cells can be oval or round in shape. They have
a large central vacuole and a dense cytoplasm. The
parenchyma tissue is located in the soft parts of the plant
such as
 
cortex 
and pith. It mainly acts as a packing
tissue, providing mechanical support. It also helps in the
storage of food. Based on the specific functions,
parenchyma can be further classified into Aerenchyma
and Chlorenchyma
.
Collenchyma – These cells are living cells and have an
elongated shape. The corners of the cell wall are
thickened. There is very little intercellular space present.
The collenchyma tissue can be located in the leaf stalks,
below the
 
epidermis 
etc. Its main function is to provide
flexibility to the plants as well as mechanical support.

8. Sclerenchyma 
–
The cells of the sclerenchyma tissue
are dead. The cell wall is very thick due to the deposition
of lignin. The cells of this tissue can be in different
shapes and sizes. They are generally located in the leaf
veins, hard coverings of the seeds and can also be found
surrounding the vascular bundle. The main function of
the sclerenchymatic tissue is to provide rigidity and
mechanical support to the plant body. They also make
the plant stiff and hard.

9. Complex Permanent Tissue
The complex permanent tissues are made up of more than one
type of cell. They coordinate together to perform the same
specialized functions in the plant body. They are classified into
two types –
 
Xylem and Phloem
Xylem – The xylem tissue is responsible for the conduction
of water and minerals from the roots to the leaves and stem.
They are tracheids, vessels, xylem parenchyma and xylem
fibres.

10. Phloem – This complex permanent tissue helps in the
translocation of food that is prepared by
photosynthesis in the leaves to various parts of the
plant. Phloem consists of four elements. They are
sieve tubes, companion cells, phloem fibres and
phloem parenchyma.