During cell division, a huge molecular complex called the kinetochore and a microtubule attach themselves to each chromosome and pull to create two daughter cells. Researchers have recently isolated the kinetochore outside of the cell, and have been able to demonstrate its functions in vitro. Surprisingly, the more tension there is on the microtubule, the more stable the connection to the kinetochore, analogous to how a Chinese finger trap ensnares a finger tighter as one tries to pull it off harder and harder.

Credit: Zina Deretsky, National Science Foundation