Chapter 4 talks firstly says about Pondicherry entering the Union of India and how india Built a zoo in the Pondicherry Botanical Garden.After Pi goes on a yap about how this zoo was like his paradise and how fun it was growing up there. Then he goes on to talk even more about zoos being more of a good thing than bad as he states that animals in zoo's dont have to find or hunt food, have shelter and such to live whereas animals in wild have to. In the end he basically says he doesn't really have an opinion on it.
Chapter 5 is about how Pi got his nickname after basically being bullied as his full name was Piscine Molitor Patel which Piscine sounds like pissing.
Chapter 6 is most likely about Pi being in India and how he loves the smell of food and how many unknown brands are here
Chapter 7 is about one of his teachers Mr Kumar, who influenced Pi to take zoology, which Pi respected and loved and met in a zoo. Mr Kumar talks about how religion is dark which Pi doesn't think religion like that. Then after Pi thinks about how he has problems with agnostics.