Question

What is the use of tissues in multicellular organisms?

Answer 1

Hint: A unicellular organism has only one cell to perform all sets of functions such as digestion, excretion, reproduction etc. which is in contrast to multicellular organisms. The complexity of an organism is synonymous with the type and range of tissues present in it.

Complete answer:
 In a multicellular organism, the division of labour can be observed wherein different sets of function are performed by separate cells. The cells which have a similar origin, appearance, dimension and perform identical functions together form tissues. Combination of tissues working as a unit to perform a specific function or a series of related functions form an organ. Further, several organs constitute an organ-system.
As we proceed from lower phylum to higher phylum, we can witness a gradual development in the function of tissues and their specificities. In higher organisms, the following sets of tissues are observed:
Epithelial tissue lines body cavities and forms glands. They occur on external and internal exposed surfaces of the body parts where they form a protective covering.
Connective tissue is the most abundant and distributed widely in the body. Its function is to bind together different tissues or organs and support various structures of the animal body.
Muscular tissue brings about movements of the body parts and locomotion of an organism through their special property of contractility.
Nervous tissue helps in the control and coordination of various body parts through their unique property of excitability and conductivity.

Note: -The word ‘tissue’ was coined by Xavier Bichat, a French anatomist and physiologist. It is derived from the French word ‘tisser’ which means ‘to weave’.
-Histology is the study of tissues. The term ‘histology’ is coined by Mayer. It is derived from the term ‘histos’ and ‘logos’ which means ‘tissues’ and ‘study’ respectively.
-Marcello Malpighi is regarded as ‘the founder of histology’.