What happens is, in deletion, our detached segment, once it breaks off, it basically moves away and it does not reattach itself onto that original chromosome. So if the detached fragment of DNA does not reattach itself onto that original chromosome, this is known as a deletion with respect to that original chromosome. Now, what about duplication? Remember, in deployed organisms, every single chromosome comes with a homologous pair. So in humans, we have 46 chromosomes, but we have 23 homologous pair of chromosomes. So let's suppose this is our homologous pair of chromosomes.