You will be given a definition of a task first, then some input of the task.
In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

A namesake protein component of this structure is detected by Toll-like Receptor 5. Tg737, whose mutation causes polycystic kidney disease in mice, is responsible for transport within this structure, which is also dependent upon complexes of IFT proteins. Y. Pestis uses a structure homologous to these to inject virulence factors into host cytoplasm, known as the Type III secretory system. They have a P, L, and MS ring in gram-negative bacteria, and in all organisms their central body is called the axonene. In Eukaryotes, they contain a 9+2 set of microtubules around a central pair and use dyenin and ATP hydrolysis to power their whipping motion. Similar to cilia, for 10 points, name these projections used by cells to swim.
Output:
Science