Tissue ~ Definition, Types , Plant and Animal Tissues

Cell: A cell is the basic structural and functional unit of a living organism. Example: Nerve cell.
Tissue: A tissue is a group of cells having a common origin, similar structure and function and held together by a cementing substance. Example: Connective tissue.
Organ: Different types of tissues working together and contributing to some specific function inside the body constitute an organ. Example: Stomach.
Organ system: Different organs coordinate to perform a specific life process and form an organ system. Example: Digestive system.
Organism: Various organ systems working simultaneously together constitute an organism. Example: Plants.

Plant Tissues

Meristematic tissue
Permanent tissue

Meristematic tissues

CHARACTERISTICS	Cells are thin-walled and made up of cellulose.
LOCATION	Located at the tips of the roots and stems, base of the node, base of the internode or at the base of the leaf.
FUNCTION	The cells of meristematic tissue divide actively, resulting in growth (increase in thickness and length) of plants.

Types of Meristematic tissues

Apical meristem
Intercalary meristem
Lateral meristem/Cambium

Apical meristem:

LOCATION	Located at the growing points of the stem, roots, branches and in growing young leaves near the tips of stems and axillary buds.
FUNCTION	Enables the root and stem to grow by increasing the length of plants.

Intercalary meristem:

LOCATION	Located at the internodes or stem regions between the places at which the leaves attach, and at leaf bases, especially of certain monocotyledons
FUNCTION	The cells are active and continuously form a number of new cells.

Lateral meristem/Cambium:

LOCATION	Present laterally (on the sides) on the roots and stem and is situated parallel to the longitudinal axis below the bark.
FUNCTION	The girth and width/diameter/thickness of the stem or root increases due to the lateral meristem.

Permanent Tissues

Formed by the division of the meristematic tissue cells that have lost their ability to multiply.

Types of Permanent Tissue

Protective tissues
Supporting tissues
Conducting tissues

Protective tissue:

CHARACTERISTICS	1. Epidermis or surface tissue. 2. Cells with thick walls.
LOCATION	Found on the surface of the roots, stems and leaves.
FUNCTION	1. Protects the underlying cells. 2. Provides protection against mechanical injury or invasion by parasitic fungi.

Supporting tissue:

CHARACTERISTICS

Provides support to the plant.

Conducting tissue: Read here

Supporting tissue

Parenchyma
Collenchyma
Sclerenchyma

Parenchyma:

CHARACTERISTICS	Consist of relatively non-specialised large, thin-walled living cells.
LOCATION	Mainly present in the soft parts of the plant such as the central pith-containing region and outer cortical region of roots and stems.
FUNCTION	Provides temporary support and maintains the shape of the plant body.

Collenchyma:

CHARACTERISTICS	Cells are living and elongated with cell walls irregularly thickened at the corners.
LOCATION	Located in the non-woody plants, leaf stalks, below the epidermis of the stems and veins of leaves.
FUNCTION	Provides mechanical support and elasticity to the young dicotyledonous plants.

Sclerenchyma:

CHARACTERISTICS	1. Consists of elongated, narrow and fibre-like cells. 2. Cells are dead, pointed at both the ends and thickened because of the deposition of lignin.
LOCATION	Located in the stems around the vascular bundle, in the veins of leaves and in the hard covering of the seeds and nuts.
FUNCTION	Provides strength and hardness to the parts of the plant.

Animal Tissues

Epithelial tissue
Connective tissue
Muscle tissue
Nervous/neural tissue

Epithelial tissue ~ Read here

Connective tissue ~ Read here

Muscle tissue

CHARACTERISTICS	Consists of elongated, narrow, muscle cells called muscle fibres.
LOCATION	Mostly attached to the bones.
FUNCTION	Helps in contraction and relaxation, which facilitates movement of the body.

Types of Muscle tissue

Striated/skeletal/striped/voluntary muscles
Nonstriated/smooth/non-striped/involuntary muscles
Cardiac/heart muscles

Voluntary muscles:

CHARACTERISTICS	Muscle fibres are long, cylindrical
LOCATION	Found attached to the bones.
FUNCTION	Help in voluntary muscle movement and locomotion.

Involuntary muscles:

CHARACTERISTICS	Muscle fibres are smooth and without striations.
LOCATION	Found in ureters, digestive tract, urinary bladder, iris of the eye, bronchi of the lungs and other internal organs.
FUNCTION	Carry out the movements which cannot be carried out by our conscious will, such as movement of food in the alimentary canal, blinking of eyes, breathing etc.

Cardiac/heart muscles:

CHARACTERISTICS	Muscle cells are short, cylindrical and have a single, centrally placed nucleus.
LOCATION	Found only in the walls of the heart.
FUNCTION	Rhythmic contraction and relaxation of cardiac muscles help to pump and distribute the blood to various parts of the body.

Nervous/neural tissue

CHARACTERISTICS	1. Made up of elongated cells called neurons. 2. Each neuron consists of three parts—a cell body, an axon and dendrites.
LOCATION	Component of the nervous system and encompasses the brain, spinal cord and nerves.
FUNCTION	Nerve cells mediate the transmission of messages from the brain to different parts of the body and vice versa.

Follow us

Need more?