Question

what is the external source of energy on which the organism depends​

Answer 1

Answer :-

"Food" is the external source of energy on which each and every living organism depends.

Explanation :-

Life forms and living structures on the earth are completely developed through carbon based compounds. These structures(organisms) require a highly significant amount of energy for carrying out their daily activities. So, they consume some other carbon based compounds which act as abundant suppliers/sources of energy. These sources are otherwise known as "Food".

Thus, from the above stated facts, it can be concluded that Food" is the external source of energy on which each and every living organism depends.