Question

WHY MULTICELLULAR ORGANISMS REQUIRE SPECIAL ORGANS FOR THE EXCHANGE OF GASES BETWEEN THE BODY AND ENVIRONMENT

Answer 1

I thik in the case of lower organisms or unicellular organism they lack any special cell and tissue which have any specific function and also not have organ level organisation and they have to play their entire body function and metabolism by the same cell .........BUT in case of multicellular organism they have organ  level organisation and also various specific cell and tissues for specific functions

Answer 2

HEYMATE!!!!

■ In multi - cellular organisms, all the cells may not be in direct contact with the surrounding environment.

■thus,simple diffusion will not meet the requirements of all the cells.

■In case of a single - celled organism, no specific organs for taking in food, exchange of gases or removal of wastes may be needed because the entire surface of the organism is in contact with the surrounding environment.

HOPE IT HELPS YOU !!!!