now, even though the you carry out a genome is mostly made of non coding DNA, there's still a bunch of different types of protein encoding genes. First and foremost are single copy genes, which is just a single copy of the unique gene in the genome. And this is probably how you pictured most jeans being in the genome. But actually some genes are tandem clusters and these air clusters of identical copies of genes that are actually transcribed simultaneously. And this is in part to help increase the output of transcription of these genes. So these tend to be genes that are needed in high demand. All once. Now you can see her in this in this picture that there are ton of different types of proteins that are jeans and code for, and among those are things we've seen, like receptors and structural proteins and cell junction proteins. Chaperones to help with folding There's a whole mess of different types of proteins that are genes encode for now. How do tandem clusters form? Well, they formed through process called gene duplication, where an extra copy of a gene is added to the chromosome and this can be due to something called unequal crossover. An unequal crossover is a misalignment of the chromite IDs during crossing over. So if you look at our example right here, we have a crossover that's going to occur. But UPS, they're swapping this sequence out over here. Oh, that's going to lead to unequal crossover, which you see right here. Boom. Now we have duplicated that be Jean. So that is how gene duplication can lead to tandem clusters. In addition, other things. So let's turn the page and take a look at some other examples.