Did you know that the nucleus, often called the “control center” of the cell, is packed with fascinating features? Despite being only about 10% of the cell’s volume, it stores all the DNA, which, if stretched out, would be about 2 meters long! The nucleolus inside the nucleus acts like a ribosome factory, producing the components needed for protein synthesis. Interestingly, not all cells have a nucleus—mammalian red blood cells lose theirs to carry more oxygen. Meanwhile, some cells, like muscle cells, have multiple nuclei to meet their high energy demands. Plus, the nuclear pores in its envelope are incredibly busy, allowing over a million molecules to pass in and out every second!