What are Tissues?
Tissues are nothing but a cluster of cells.
In a single-celled organism like amoeba, all the functions of the organism’s body including
respiration, digestion, locomotion, or excretion are carried out by a single cell.
However, in multicellular organisms like cats and dogs, these functions are carried out by a group of cells called tissues.
Single-celled organisms Multicellular organisms
What are the functions of tissues?
Tissues located at specific places, carry out specific functions. This is called ‘Division of
labour’. For example, the tissues in the lungs are for respiration and the tissues in the stomach perform the function of digestion.
Tissues in animals
Animals move from place to place. So their tissues experience wear and tear and need constant maintenance. Hence, almost all tissues in animals are living tissues. These tissues need
nutrition, which they get from the organism’s body.
Animals exhibit uniform growth throughout their body and have tissues that divide, which are located throughout their body.
Different tissues in the human body
Some examples of tissues in animals are muscles that help movement by contraction and relaxation and blood, which is a connective tissue that helps transport nutrients, hormones and waste materials.
Tissues in plants
Plants are stationary and their movement is restricted. So, plants have dead tissues, which need very little maintenance and serve the purpose of giving mechanical support to plants.
Types of tissues in plants
There are two types of tissues in plants:
● Dividing type of tissue
These tissues can divide throughout their lifetime. In plants, growth is restricted to only some specific parts. Thus, these tissues that can divide are located in these parts.
● Non-dividing type of tissue
These tissues do not have the ability to divide. Parts that do not grow beyond a specific limit have the non-dividing tissues.