Answer the following question given this paragraph: 

There are about 22,000 genes in every human cell. Does every human cell have the same genes? Yes. Does every human cell make the same proteins? No. In a multicellular organism, such as us, cells have specific functions because they have different proteins. They have different proteins because different genes are expressed in different cell types (which is known as gene expression ).


Q: Every human cell has the same what, and each cell has thousands of them?


A:
genes