Originally transmitted in 2 parts on ITV. Part One aired 26th of January 1992 and Part Two aired February 2nd 1992. Excluding adverts, each episode was 1 hour and 18 minutes.
In the novel the show is based upon, the clones are exactly that - exact physical replicas of Joanna. To allow different actresses to take the part of each clone in the TV adaptation, it was explained that different host cells had been used to breed the clones, meaning they were similar, rather than identical, in appearance.