The genes are located within the chromosomes. These are specific sections of DNA that contain the instructions for making proteins.
In Eukaryotic Cells (such as human, plant, and animal cells)- The genes are situated on chromosomes and are composed of DNA and proteins. Chromosomes are situated within the nucleus of the cell. Additionally, mitochondria and chloroplasts (plant cells) contain certain genes.
In prokaryotic cells (such as bacteria)- The genes are located on a single circular DNA molecule that floats in the cytoplasm, as prokaryotes lack a nucleus.