If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Unit 18: Gene regulation

About this unit

You have tens of thousands of genes in your genome. Does that mean your cells express all of those genes, all the time? Not by a long shot! Even an organism as simple as a bacterium must carefully regulate gene expression, ensuring that the right genes are expressed at the right time. Learn more about the mechanisms cells use to turn genes "on" and "off."

Do you think of bacteria as boring blobs? How about as little calculators? Bacterial gene regulation networks essentially perform logic operations using proteins and DNA. Learn more about how bacterial genes are organized and how their expression is regulated.
In multicellular eukaryotes (like you!), each type of cell in the body must express its own unique set of genes. Learn more about the many ways that eukaryotic gene expression can be regulated.