In the first movie we see Kane being infected by having an alien attached to his head. In Prometheus we see something different, but I don't know if it's right to affirm that he was infected with the same type of alien.
So what are the possible ways to get an alien exploding out of your chest?
There are two questions here, which you might want to clarify, but I can try answering them both:
There is one confirmed way to have get an alien exploding out of your chest, which is to have a Facehugger (of whatever subspecies) stick a xenomorph embryo down your throat.
There are quite a few more ways to be 'infected' with an alien that we've seen so far, throughout all the Alien franchise movies including Prometheus. Infection methods include a). facehugger implantation; b). 'eggmorphing', in which adult xenomorphs capture and cause prey to slowly metamorphose into eggs; c). victims imbibe the 'black fluid' as in Prometheus, either through controlled David-style dosage or via less-controlled worm delivery, and turn into zombie-like berserkers; d). have sex with a black fluid-infected person and become impregnated by a facehugger variant; and finally e). have your blood sampled while you are incubating a xenomorph embryo, then be cloned from the sample with some some human/Xenomorph genetic overlap.
The life cycle of the Xenomorph as depicted in the Alien franchise bears almost no resemblance to the life cycle depicted in the movie Prometheus.
The xenomorph's life cycle is actually not explained in the first Alien movie, and only becomes clear in the sequel, Aliens. There, the cycle is presented as something slightly similar to an ant's, but not quite the same as any species that I know of.
A Queen xenomorph lays eggs. The eggs hatch into face-huggers. The face-huggers attach themselves to a host organism, usually a human, and implant a different kind of egg into the host's throat; the face-hugger then dies. This egg eventually hatches into a chest-burster, which grows into an adult xenomorph. I'm not sure if we ever learn whether any adult xenomorph can become a Queen, but it is at least plausible. Most of the time, however, the adult xenomorphs seem to serve as drones or slaves, protecting the queen and her eggs, collecting hosts, trapping them in the lair, or hive, and possibly serving other functions as well.
In the movie Prometheus, on the other hand, the life cycle is wildly different from this. David finds bottles of a strange, black liquid, which he surreptitiously places in Charlie's drink. Charlie consumes the liquid, has sex with Elizabeth, impregnates her, and becomes quite ill. The fetus, or zygote, or whatever you want to call it, is a monstrosity. She undergoes a procedure to remove the monstrosity, which apparently grows into a much larger creature very quickly. Near the end of the film, the monstrosity has become an enormous version of a face-hugger, and attacks one of the "Engineers". The Engineer's corpse later splits open, and something very similar to a xenomorph crawls out.
Note: This answer is based on the first two movies in the Alien franchise and the movie Prometheus. If there is some other information about the issue in other sources, I don't know enough about it to use it in my answer.
So far (xenomorph) the way to get infected is by the best thing you have ever seen, the facehugger. So it grabs on to your head and puts a cancer down your throat. That cancer then makes a chestburster by mutating the organs in a way so that the embryo can then form from your flesh (yes your flesh). Then that chestburster will then grow bigger, about a foot (my estimation), and then grows into a cocoon as seen on Aliens vs Predator Extinction. Then it grows into a adult xenomorph.
The black liquid then gets in a host then from sexual intercourse will get a trilobite (squid like creature from Prometheus) in the 2nd host and grow at an alarming rate into a bigger version of itself. Then if not removed it might burst from the chest, but in Prometheus it gets removed and turns into a hulking 10 feet creature like a giant facehugger.
Are there any other ways to get infected by a xenomorph?
