Question

Is each of the organ useful to organism

Answer 1

Yes, every organ seems to be quite useful for the organism because every organ does its own specific work or task individually.

Human beings have five important organs and surviving without any of these will not be quite possible.

The important organs are kidneys, liver, lungs, heart and brain. These organs are divided into different organ systems.

Answer 2

no the vestigial organs are not useful
like the appendix , ear muscles, wisdom teeth
etc