Every time one of your cells divides, it literally rips its own chromosomes apart. That's what you're seeing in this color-enhanced image by Patricia Wadsworth, which won a prize in the BioScapes digital imaging contest earlier this month. All the stretchy yellow lines are your chromosomes, currently being yanked from either end and about to separate down the middle. We still don't fully understand how or why this happens.
After the ripping, each set of chromosomes will go into different cells, and the miracle of our genetic weirdness can continue. Things don't always go this well. Sometimes the chromosomes don't separate completely, and one cell gets an extra set. And sometimes cells go through the division process, called mitosis, way more often than they are supposed to. That's usually what we call cancer, and it leads to tumors and other out-of-control cell growth. Nice to know that such a dangerous process makes a pretty little picture.
Wadsworth Lab [artist's site]