What are tissues????????
Answers
Explanation:
Tissue- In multicellular animals a set of similar cells along with intracellular substance and perform a specific work such an establishment is called a tissue.
Tissues are of four types
1. Epithelial Tissue- They arise from ectoderm, Endoderm and mesoderm. They perform their function in covering, protection, diffusion, secretion and absorption etc.
2. Connective Tissue- They arise from mesoderm. They play important role in connection of structures, providing support to the body, transportation of substance in the body etc.
3. Muscular Tissue- They arise from mesoderm and they play important role in contraction and relaxation which help in movement of the body and locomotion as well.
4. Nervous tissue- It arise from ectoderm. They help in generation and conduction of impulses in the body.
Answer:
In biology, tissue is a cellular organisational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Types of animal tissues
(1). Epithelial tissue⤵⤵⤵
The epithelial tissues are formed by cells that cover the organ surfaces, such as the surface of skin, the airways, the reproductive tract, and the inner lining of the digestive tract. The cells comprising an epithelial layer are linked via semi-permeable, tight junctions; hence, this tissue provides a barrier between the external environment and the organ it covers. In addition to this protective function, epithelial tissue may also be specialized to function in secretion, excretion and absorption. Epithelial tissue helps to protect organs from microorganisms, injury, and fluid loss.
(2). Connective tissue ⤵⤵⤵
Connective tissues are fibrous tissues made up of cells separated by non-living material, which is called an extracellular matrix. This matrix can be liquid or rigid. For example, blood contains plasma as its matrix and bone's matrix is rigid. Connective tissue gives shape to organs and holds them in place. Blood, bone, tendon, ligament, adipose, and areolar tissues are examples of connective tissues. One method of classifying connective tissues is to divide them into three types: fibrous connective tissue, skeletal connective tissue, and fluid connective tissue.
(3). Muscular tissue⤵⤵⤵
Muscle cells form the active contractile tissue of the body known as muscle tissue or muscular tissue. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle tissue is separated into three distinct categories: visceral or smooth muscle, found in the inner linings of organs; skeletal muscle, typically attached to bones, which generate gross movement; and cardiac muscle, found in the heart, where it contracts to pump blood throughout an organism.
(4). Nervous tissue⤵⤵⤵
Cells comprising the central nervous system and peripheral nervous system are classified as nervous (or neural) tissue. In the central nervous system, neural tissues form the brain and spinal cord. In the peripheral nervous system, neural tissues form the cranial nerves and spinal nerves, inclusive of the motor neurons.
Types of plant tissues
(1). Meristematic tissues⤵⤵
Meristematic tissue consists of actively dividing cells, and leads to increase in length and thickness of the plant. The primary growth of a plant occurs only in certain, specific regions, such as in the tips of stems or roots. It is in these regions that meristematic tissues are present. Cells in these tissues are roughly spherical or polyhedral, to rectangular in shape, and have thin cell walls. New cells produced by meristem are initially those of meristem itself, but as the new cells grow and mature, their characteristics slowly change and they become differentiated as components.
(2). Permanent tissues⤵⤵
Permanent tissues may be defined as a group of living or dead cells formed by meristematic tissue and have lost their ability to divide and have permanently placed at fixed positions in the plant body. Meristematic tissues that take up a specific role lose the ability to divide. This process of taking up a permanent shape, size and a function is called cellular differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissues. There are 3 types of permanent tissues:
(1). Simple permanent tissues
(2). Complex permanent tissues
(3). Special or secretory tissues (glandular).
➡ Simple tissues⤵⤵⤵
A group of cells which are similar in origin; similar in structure and similar in function are called simple permanent tissue. They are of four types:
(1). Parenchyma
(2). Collenchyma
(3). Sclerenchyma
(4). Epidermis
➡Complex permanent tissue
The complex tissue consists of more than one type of cells which work together as a unit. Complex tissues help in the transportation of organic material, water, and minerals up and down the plants. That is why it is also known as conducting and vascular tissue. The common types of complex permanent tissue are:
(1). Xylem or wood
(2). Phloem or bast.