The cell part that contains the genes for heredity is the nucleus.

Here's why:

* Genes are located on chromosomes: Genes are segments of DNA that carry the instructions for building and maintaining an organism. These DNA segments are organized into structures called chromosomes, which are found within the nucleus.

* The nucleus is the control center: The nucleus serves as the cell's control center, containing the genetic blueprint (DNA) that directs all cellular activities.

Let me know if you'd like more details about genes, chromosomes, or the nucleus!