Given a scientific passage and an answer, generate a question for the given answer.

Example Input: Passage: The amount of material left over after a certain number of half-lives can be easily calculated. Answer: pheromone
Example Output: What term is used to describe a chemical released by an animal that affects the behavior or physiology of animals of the same species?

Example Input: Passage: To ensure that no more than one sperm fertilizes the egg, once the acrosomal reactions take place at one location of the egg membrane, the egg releases proteins in other locations to prevent other sperm from fusing with the egg. If this mechanism fails, multiple sperm can fuse with the egg, resulting in polyspermy. The resulting embryo is not genetically viable and dies within a few days. Answer: polyspermy
Example Output: What is the term for if multiple sperm fuse with an egg?

Example Input: Passage: Protein Structure. The structure of a protein starts with its sequence of amino acids. What determines the secondary structure of a protein? What are two types of secondary protein structure?. Answer: amino acids
Example Output:
What does the structure of a protein start with?