Question

Why unicellular organisms do not require specific organs and why it is not so multicellular organisms

Answer 1

Dear student,
A unicellular organism is made up of a single small cell that can perform all the necessary functions. In this single cell all types of physiological processes like respiration, digestion, reproduction, excretion etc. are taking place like the higher organism. It contains several cell organelles like mitochondria, ribosome, vacuoles etc. to perform different functions like mitochondria are responsible for respiration, contractile vacuoles act as digestive system, lysosome as excretory system etc. The cell divides into two for reproduction by the process of binary fission,
Multi cellular organisms like animals, humans have to perform large number of functions like respiration, digestion etc. So, in order to regulate all functions properly there is division of labour in such organisms. Particular group of cells that makes a tissue which in turn makes an organ becomes specific to perform a particular function.
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