What is the utility of tissues in multi-cellular organisms?

In unicellular organisms, a single cell performs all the basic functions such as respiration, movement, excretion, digestion, etc. 

But in multicellular organisms, cells are grouped to form tissues. These tissues are specialised to carry out a particular function at a definite place in the body. For example, the muscle cells form muscular tissues which helps in movement, nerve cells form the nervous tissue which helps in transmission of messages. This is known as division of labour in multicellular organisms. It is because of this division of labour that multicellular organisms are able to perform all functions efficiently.

In multicellular organisms, the body system is based on the division of labour. It means the cells performing a specific function are grouped together to form a particular tissue. The different tissues are organized in a way to provide highest efficiency in functioning of the body.

In human beings, muscle cells contract and relax to cause movement, nerve cells carry messages, blood flows to transport oxygen, food, hormones and waste material and so on. This is the utility of tissues in multi-cellular organisms.

In multicellular organisms, the different types of tissue performed different functions. Since a particular group of cells carry out only a particular function, they do it very efficiently. So, multicellular organism possess a definite divison of labour.