What is a unit of a novel?

Read the sentence from last lecture by randy pausch. all right, so what we’re not talking about today, we are not talking about cancer, because i spent a lot of time talking about that and i’m really not interested. pausch tells his audience this because he wants them to know that

How did the older men calm the younger ones down when they learned from some of the prisoners where they were? (chapter 3 of the book night)

Short stories by male dark romantic writers explored insanity, also called madness, as suffered by young women. what is the tone of this passage?