Tissues Class 9 Notes Science - Chapter 6

Chapter: 6

What Are Tissues ?

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A group of cells that are similar in structure and/or work together to achieve a particular function forms a tissue.

Plant Tissues

Meristematic Tissue
(Immature cells capable of divisions)

➥ Apical Meristem (Present at the growing tips of stems and roots responsible for increase in length)
➥ Intercalary Meristem (Present at the bone of internodal regions, responsible for secondary growth)
➥ Lateral Meristem (Present in lateral regions, responsible for increase in width of the plant)

Permanent Tissue
(Mature cells incapable of divisions)

Simple (Made up of only one type of cells)

➥ Parenchyma (Living tissue stores and condusts food, water and minerals)
➥ Collenchyma (Living tissue provides strength and flexibility to growing part of the plant)
➥ Sclerenchyma (Dead tissue, provides mechanical support)

Complex (Protecting and supporting)

➥ Xylem	➥ Phloem
(Conducts water and mineral from the root to the steam and leaves)	(Transport food from the leaves to the other parts)
Tracheids (Elongated tube like with thick lignified walls)	Sieve tube elements (Long, tube like, arranged longituinally)
Vessels (Long cylindrical with lignified walls)	Companion cells (Specialised parenchyma)
Fibres (Highly thickned walls)	Phloem parenchyma (Long cylinrical, stores food)
Xylem parenchyma (Living cells, thin walled)	Phloem fibre (Made of sclerenchyma, thick cell wall)

Animal Tissues

Epithelial tissue	Muscular tissue	Connective tissue	Nervous tissue
(Protective tissue)	(Responsible for movements in body)	(Linking and supporting tissues or organs of body)	(Receives, conduct and transist electrical impulse, made up of nervous or nerve cells)
Glandular (specialised tissue)	Voluntary muscle	Bone (strong, non-flexible tissue compound of bone cells and hard matrix of calcium and phosphorus)
Salivary gland	(Activities under the control of nervous system) or Skeletal muscle
Unilayer
Multilayer	Involuntary muscle	Ligament(Elastic tissue with little matrix, connect bone to bone)
Stratified squamous epithelium	(Responsible for involuntary movement in body)	Tendous (Fibrous tissue with great strength and limited flexibility – connect muscle to bone)
Squamous (Thin and flat forming living of blood vessels, alveoli, mouth and Oesophagus)	Cardiac Muscle (Cylindrical, branched, uninucleate and straited)	Cartilage (Alidely spaced cells, smoothens bone surface at joints)
Cuboidal (Cube shaped, form livings of renal tubule and duct of salivary glands where it provides mechanical support)	Smooth/unstriated muscles or Visceral Muscle (Located in the inner wall of hollow visceral organs like alimentary canal, etc.)	Areolar connective Tissue (Found between skin and muscle around blood vessels and nerves and in bone marrow)
Columnar (Pillar like)
Non-ciliated (Tall cells in inner linings of stomach and intestine)
Ciliated columnar epithelium (Tall epithelial cells with hair like projections, present in inner lining of respiratory tract)