Instructions: 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.
Input: In protosteles, it is in the center of the stem, and in angiosperms, rays, fibers, and axial parenchyma cells make up one form of it. Its meta- type is distinguished by wider tracheids, and its most specialized structure is known as the trachea. Transpirational pull causes negative pressure to form in it, and it is used to transport water and minerals from the roots to the rest of the plant. FTP, the cambium separates what part of a plants vascular system from the phloem.
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Science