This is the story of 6 or 7 scientists on the space station who receive a sample of life from Mars. They try to get the life to grow and it does and it becomes bigger, stronger and smarter and kills them all and then is brought to earth.
All life here will die!
This movie is rated R but that is dumb, though the movie uses the word fuck and fucking a few times.
pg13 would have been appropriate, since kids can certainly handle deaths and profanity!