All the 150 Kanto Pokemon exist there as well as a good bunch of Pokemon from Gen 2 and 3. You can't get all of the Pokemon without trading with somebody with Pokemon Emerald.
there are 151 between leafgreen and fire red
There are 151 in total between fire red and leaf green
YES
You have to trade it from Fire Red
you don't you get it in fire red
you cant
bellsprout and what they evolve into
The same Pokemon in fire red, except for a couple.
You can't. have to trade from fire red
150 Pokemon for fire red and leaf green (not including legedaries or hoen and johto Pokemon)
Pokemon fire red is better.
You can only catch them in Pokemon fire red.