Class 9 Science – Chapter 2: Tissues
(Biology) Notes
What is a Tissue?
A tissue is a group of similar cells that work together to perform a specific function.
In multicellular organisms, cells combine to form tissues.
Tissues make the body more organized and efficient.
Examples:
Muscle tissue helps in movement.
Blood transports oxygen and nutrients.
Why are Tissues Important?
Division of work among cells.
Better efficiency.
Faster body functions.
Helps in growth and repair.
Forms organs and organ systems.
Types of Tissues
There are two main types:
1. Plant Tissues
2. Animal Tissues
PLANT TISSUES
Plant tissues are of two types:
1. Meristematic Tissue
2. Permanent Tissue
, Meristematic Tissue
Definition
Meristematic tissue consists of actively dividing cells responsible for plant growth.
Characteristics
Cells divide continuously.
Thin cell walls.
Dense cytoplasm.
Large nucleus.
Vacuoles are absent or very small.
Cells are closely packed.
Functions
Increases plant length.
Increases plant thickness.
Helps in healing damaged parts.
Types of Meristematic Tissue
1. Apical Meristem
Present at root and shoot tips.
Increases the length of the plant.
Responsible for primary growth.
2. Intercalary Meristem
Present at the base of leaves or internodes.
Helps grasses grow again after cutting or grazing.
3. Lateral Meristem
Present along the sides of stems and roots.
Increases the thickness of the plant.
Responsible for secondary growth.
Permanent Tissue
(Biology) Notes
What is a Tissue?
A tissue is a group of similar cells that work together to perform a specific function.
In multicellular organisms, cells combine to form tissues.
Tissues make the body more organized and efficient.
Examples:
Muscle tissue helps in movement.
Blood transports oxygen and nutrients.
Why are Tissues Important?
Division of work among cells.
Better efficiency.
Faster body functions.
Helps in growth and repair.
Forms organs and organ systems.
Types of Tissues
There are two main types:
1. Plant Tissues
2. Animal Tissues
PLANT TISSUES
Plant tissues are of two types:
1. Meristematic Tissue
2. Permanent Tissue
, Meristematic Tissue
Definition
Meristematic tissue consists of actively dividing cells responsible for plant growth.
Characteristics
Cells divide continuously.
Thin cell walls.
Dense cytoplasm.
Large nucleus.
Vacuoles are absent or very small.
Cells are closely packed.
Functions
Increases plant length.
Increases plant thickness.
Helps in healing damaged parts.
Types of Meristematic Tissue
1. Apical Meristem
Present at root and shoot tips.
Increases the length of the plant.
Responsible for primary growth.
2. Intercalary Meristem
Present at the base of leaves or internodes.
Helps grasses grow again after cutting or grazing.
3. Lateral Meristem
Present along the sides of stems and roots.
Increases the thickness of the plant.
Responsible for secondary growth.
Permanent Tissue
