Cat Whines

Question
I have a male cat, who is just over one year old, he was born on
Father's Day, along with his brother, who I also own.  He has
been whining throughout our apartment for the last day.  It
doesn't matter what time it is.  He has been neutered and has
never whined this long.  Most of the time when he whines and
then escapes he goes to my mother's apartment and sits there.

Answer
Check the litter box to ensure that he is urinating.  The crying could be due to pain from difficulty of not being able to eliminate or some other illness.  

If he is urinating normally and having normal bowel movements, eating and drinking, then I would be concerned about a behavioral issue.

Best bet is to take him to the vet for a checkup.