Despite its microscopic size, every cell is an incredibly complex biological system. Inside, thousands of chemical reactions take place every second, producing energy, synthesizing proteins, copying DNA, and sustaining life itself. Cells make all forms of life possible. Some become neurons, transmitting electrical signals at remarkable speeds. Others develop into muscle cells, allowing us to move. Others form our skin, bones, blood, and nearly every organ in the human body. Even bacteria, which

Why don't we have just ONE nostril?