Here's a breakdown:

* Cell: The basic building block of all living organisms.

* Nucleus: A membrane-bound organelle within a cell that contains the cell's genetic material.

* Chromosomes: Long, thread-like structures made of DNA and proteins, located within the nucleus.

* Genes: Segments of DNA that contain the instructions for building and maintaining an organism.

So, to summarize:

Genes are located on chromosomes, which are found inside the nucleus of cells.