a plant cell is a kind of cell & a cell nucleus is a part of a cell -> a room obstacles is a whole of a vegetable room a cell nucleus is a part of a plant cell  a cell nucleus is a part of a plant cell & chloroplast is a part of a plant cell & a room window is a whole of a vegetable room for skunk and protecting the room waves -> a cell nucleus, chloroplast and a cell wall are part of a plant cell