Here's why:

* Genes are segments of DNA that contain the instructions for building and maintaining an organism. They determine traits like eye color, hair color, and height.

* Chromosomes are long, thread-like structures made up of DNA and proteins. They are found in the nucleus of every cell.

* Each chromosome contains many genes. These genes work together to control the cell's functions, including:

* Protein synthesis: Genes provide the instructions for making proteins, which carry out a wide range of cellular tasks.

* Cell division: Genes regulate the process of cell replication.

* Cellular metabolism: Genes influence how the cell uses energy and breaks down nutrients.

So, chromosomes are the structures that contain the genes which, in turn, hold the information controlling the cell's activities.