by a action replay or if your game is a download game
No.
You can't. Pokemon Sapphire version and Pokemon Ruby version where released in 2003 for the Game Boy Advance , there not able to be played on the Game Boy Color, you could sell you're Game Boy Color and get a Game Boy Advance sense Game Boy Color games can as well be played on the Game boy Advance.
You have to migrate it ro trade it from another ds Pokemon game that has it.
you need to have seen every Pokemon in the game to proceed
Yes Pokemon platnium is the third game in the generation VI games go to Bulbipedia for more info
You must trade or import it from a GBA game
Yes u can. I played fire red on my game boy advance before i got my ds.
Pokemon leaf green is a Nintendo Game Boy Advance game cartridge. This can be played on the following systems: Nintendo Game Boy Advance Nintendo Game Boy Advance SP Nintendo Game Boy Advance Mini Nintendo DS Nintendo DSlite Nintendo Gamecube Gameboy player
????Pokemon Ranger is a separate game
No.
yes you can