The Same Way You Would Save It On GBA But Some Games are Not Savable.
Gameboy games and DS games are sold separately but the Nintendo DS can play any type of Gameboy game.
Yes, you can!
sadly no you can't play the game boy advanced gamed or DS games on the original game boy because they have different shapes.
go to a zone
No. Only Generation I (Red, Blue, Yellow) can trade with Generation II (Gold, Silver, Crystal). There is no way to trade beyond that.