Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: Sperm are tiny cells. In fact, they are the smallest of all human cells. They have a structure that suits them well to perform their function. Answer: sperm
Solution:

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
What type of cells are the smallest of all human cells?