Factual error: There is no possible method of "fusing" the genetic material of a common housefly (Musca domestica) and a human. The housefly has twelve chromosomes, humans forty six. There is no way to combine the two in order to produce a viable organism. Thirty four of the human chromosomes would have no matching chromosome to "fuse" with, meaning the physical characteristics coded by those genes would not form. The Brundlefly would be missing three quarters of his human body.
The Fly (1986)
1 factual error - chronological order
Directed by: David Cronenberg
Starring: Jeff Goldblum, Geena Davis, John Getz, Joy Boushel
Plot hole: In any given volume of air, there are any number of tiny, living organisms; dust mites, viruses, bacteria, etc. Why did the teleporter combine Seth's DNA only with the fly that was in the chamber? If he had taken the "floating organisms" into account in his calculations and programming, then why would he not have excluded ALL foreign DNA?
Tawny: Are you a body builder, or something?
Seth Brundle: Yeah, I build bodies. I take them apart, and put them back together again.
Question: Well into the movie, Seth's computer, which uses voice recognition, can no longer recognize his voice due to his transformation. How then, did he hook up the three telepods and execute the final sequence if he couldn't get into his computer?
Chosen answer: He just used the keyboard. We see him typing on it several times before this scene, so the computer is not voice command only.
Suggested correction: There's no possible way of teleporting physical objects either, but it happens in this movie. This is science fiction. These kinds of "factual errors" are not valid.
Phaneron ★
The film presents no scientific explanation for "teleportation" but does for "genetic merging." Teleportation is possible in this film's universe, but "genetic merging" is impossible in any universe.
Genetic merging is possible in this film's universe; that's the whole point. It doesn't matter if the explanation doesn't stack up, it still works.