Okay, one of these face-grabber things attaches itself to you, knocks you out, shoves a tube down your throat and drops an embryo. Soon, the face-grabber falls off and you revive. You walk around just fine for a few days, then the embryo (somewhat larger) bursts out of your stomach, which kills you, and the embryo scoots and squeals away to kill everyone else on your spaceship or planet or whatever.
My question, Officer Ripley, is: If you only serve as a temporary host for an embryo, which originates, grows and bursts out as a completely separate organism, then what makes anyone think that cloning YOU will ALSO produce one of the parasite organisms?
I once asked Congresswoman Sheila Jackson Lee if she ever felt guilty about receiving automatic salary increases (unless congress acts to avoid them), and she just looked at me with a blank stare. I would expect that same sort of reaction from the screenwriter who came up with THIS premise.