Why would I need a bios file for genesis games on Kega Fusion?

I know I don't necessarily need it but I want to know why I would want to use a bios file (eg: Sega Mega-CD Model 1 BIOS v1.00 (1992)(Sega)(Eu)). What I am trying to say is is there a benefit in using this bios file for more accurate emulation, etc?

The reason why I ask is I want to see what this does but I don't want to mess up my settings in the process.

I do not know of any games that needs the bios for Kega but some games on virtual boy advance ask for a bios its a good idea to try to find all the bios files to every emulator that way you will be ready if you need it one day

This is probably a question best asked at Kega's own forums. Most emulators already emulate the necesarry BIOS codes, but there are games or systems (PSX for instance) that absolutely require a BIOS.

Just the way it is I guess