Question: How was the mother cell discovered? Was it man made or natural?
Question: How come Chloe didn't tell the other group what happened when she was kidnapped and held by Alves after she been rescued? She told the group on her cell phone that she will talk about it later but she never did.
Answer: My assumption would be a simple "it's not important" explanation. It's one of those typical selfless things in film where the characters don't provide specific information as to not make other characters worry about them, in addition to her intelligence background she may have just thought it would distract them from their main goal. Nothing really "happened" to her that would really drive plot development either, as she was quickly rescued from the situation. A similar example would be when Chloe called right after the speech she gave, Jamie doesn't tell her that Jackson was shot, just that he was hurt and that he'll be OK. We can assume that she just doesn't want Chloe to worry about him.
Answer: In the episode "Blame It on Leo", Leo Butler, who use to work for Reiden, tells the group about the "mother cell." He explains it's Reiden's molecule vector. So it's something Reiden created. In real life science, vector cells are used to introduce DNA sequences from one organism to another. There are a variety of ways for this to occur, however, in the show not much explanation is given about how Reiden's mother cell works (and tends to bend how it works to the will of the plot).
Bishop73