In plants, there are two basic types of tissues, which are as follows.
Meristematic or embryonic tissues:
These tissues are present in the root and shoot tips as apical meristems and divided and redivide to add primary tissue for elongation (length) of stems or roots. such growth is called primary growth. meristematic cells are also found on the lateral sides of roots and stem as lateral or intercalary meristem of cambium and their division adds secondary tissue increasing the thickness of stems and roots. this is called secondary growth.
It is formed from meristematic cells. the cells of this tissue do not divide.
Tt is made up of one type of cell forming a uniform or homologous uniform mass. simple tissues may further be divided into the following types on the basis of their structure.
It consists of living cells. these have intercellular spaces. they are present in all the soft parts of plants. it is food-storing tissue.
They are living cells. they are found in the cortex of the midrib and petioles of leaves and in young herbaceous stems where they provide strength to the parts of plants.
They are thick-walled, long narrow, and dead cells. they become hard by deposition of chemicals like lignin in their cells walls and thus provide hardness and strength and support to plant. no protoplasm is present in them.
complex or compound tissues:
They are mainly of two types: (i) Xylem and (ii) phloem.
Epidermal tissues: the cells in them are very compactly arranged and there is no intercellular space between them.
the epidermal serves to protect the inner parts of plants.
Ground tissues: they are composed of thin-walled parenchymatous cells which are formed from meristematic tissue.
they provide help in the storage of food and water in plants.
Supporting or mechanical tissues: These tissues are various-shaped and provide rigidity and support to the plant, e.g. collenchyma, sclerenchyma.
they provide strength and flexibility to the plant.
Conducting or vascular tissues: the permanent tissues in plants that help in the transportation of material are called conducting or vascular tissues. they are two types.
1. xylem tissue
2. phloem tissue
Xylem Tissue: this vascular tissue provides strength and transports water and mineral salts in plants upwards from the soil to the leaves. The xylem consists of sclerenchyma vessels and fibers.
Phloem Tissue: the phloem is made up of living cells like sieve tubes which conducts food from leaves to various parts of plants both upwards and downwards. Xylem and phloem together form vascular bundles in the stem while they remain separate from each other in the roots.
Define tissues, organs, and organ systems.
Tissues: a tissue is made up of many cells of one or a few types in which the cell of each type have a more or less identical structure or function, nervous tissue in animals conducts impulses and the phloem of plants carries food.
Organs: An organ is a functional unit consisting of several tissues grouped together. An organ cannot function alone in isolation e.g. heart, leaf, etc.
System: The system usually refers to a group of organs that interact with and interdepend on each other to form a complete organ system, e.g. the stomach is one organ forming part of the digestive system.
Types of permanent tissue of plants
- Epidermal tissues
- Ground tissues
- Supporting tissues
- Conducting avascular tissues (xylem and phloem)
Types of permanent tissue of animals
- Epithelial tissue
- Connective tissues
- Muscular tissue
- Nervous tissue
Kinds of simple tissue
- Collen cymas
Supporting tissue of plants