In what ways is unity achieved through contrast in Act, I Scenes iii - v?

Scene iii focuses on Ophelia and her relationships with her father and brother; by the end she has been told not to associate with Hamlet because his motives are untrustworthy.  Scene iv focuses on Hamlet and his search for the ghost and the ghost appearing and asking Hamlet to follow.  Scene v focuses on the ghost's revelation of the secret murder.  The unity that is achieved is first in the family relationships which are guided by the father and what he asks (or commands) his children to do for him.  All children agree to do what the father asks, although Laertes plans to do what he chooses in Paris; Ophelia agrees to her father's commands very grudgingly; Hamlet agrees to avenge the ghost, but is nervous about exacting revenge since the ghost might try to trick him as ghost could do.