Plant Tissues

Synopsis

Levels of Organisation

• Cell: The basic structural and functional unit of a living organism is called a cell. Examples: Nerve cell, muscle cell 
• Tissue: A group of cells with a common origin and similar structure and function being held together by a cementing substance forms a tissue.
  Examples: Connective tissue, meristematic tissue 
• Organ: Different types of tissues working together and contributing to some specific function of the body constitute an organ.
  Examples: Stomach, heart 
• Organ system: Different organs coordinate to perform a specific life process and form an organ system.
  Examples: Digestive system, nervous system 
• Organism: Various organ systems working simultaneously together constitute an organism.
  Examples: Plant, animal
  

Importance of Tissues

• Formation of tissues ensures division of labour in multicellular organisms.
• Tissues organise to form organs and organs form organ systems.
• The workload of individual cells decreases due to the origin of tissues.
• Improved organisation and higher efficiency ensure greater survival of multicellular organisms.

Differences between Plant and Animal Tissues

Plant Tissues

 

A. Based on Origin and Development

Permanent Tissue

Types of Permanent Tissues

Simple Permanent Tissue

• These tissues are made up of same type of cells which are similar structurally and functionally. 
• They include two types of tissues: 

• Protective Tissue
• Supporting Tissue

A. Protective Tissue

• It is found on the surface of the roots, stems and leaves. 
• It consists of cells with thick walls. 
• It provides protection against mechanical injury or invasion by parasitic fungi.
• There are two types of protective tissues in plants: 

• Epidermis
• Cork
  
  

• These tissues are made up of more than one type of cells which work together as a unit.
• It is also known as conducting or vascular tissue.

Conducting Tissue (Vascular Tissue)

• It is present in stems, roots and leaves. 
• It provides a passage for water and dissolved materials to move up and down in the plant body.
• There are two types of conducting tissues in plants:

• Xylem
• Phloem
  

 

Differences between Meristematic and Permanent Tissues