Yes and no... You can do that "offline" but you have to have a friend or something along those lines playing as a human. But no you can not be infected by yourself.
yes
zombie mode is on ps3 you dummy
No. Unfortunately not
yes yes
wa bybi
Not on the same xbox/ps3 no unfortunately.
No
l4d2 it has more zombies and its more funner.
Buy both but i prefer L4d2 if you want to kick some zombie @ss and if you want terrorist @ss by Mw2 btw im buying mw2(on ps3) first then l4d2(probably PC)
No, it is not possible to clone a zombie kitten.
Zombies will attack anyone who is not a zombie. In this case the infection is an extreme variant of rabies, which causes violent behaviour in order to spread itself through fuids such as saliva.
Yes, you can, but I'm not sure, if its possible to play with friends offline...