lines 100-115 what does the father do when gregor oversleeps

I don't have the same line numbers as you do. Realizing that Gregor is still home, his father and sister also begin calling him through the doors, so Gregor tells them that he is getting up, trying to control the change in his voice, which he believes to indicate the start of a cold. As Gregor's sister attempts to come into his room, he is glad for his habit of locking all his doors.