Question
Sat November 05, 2011 By:

Which organisms are called as primitive and how are they different from the so called advanced organisms?

Expert Reply
Sat November 12, 2011
Primitive organisms are those which have ancient body designs and have not changed much. They have simpler body design and are also called lower organisms.  On the other land, the organisms that have acquired more complex structure and body design relatively recently are called advanced organisms. They have complex body design and are called higher organisms.
These advanced or 'younger' organisms acquire more complex structures during evolutionary time to compete and survive in the changing environment.
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