You will be given a definition of a task first, then some input of the task.
Given a scientific passage and an answer, generate a question for the given answer.

Passage: The amino acid sequence is the primary structure of a protein. As explained in Figure below , a protein may have up to four levels of structure, from primary to quaternary. The complex structure of a protein allows it to carry out its biological functions. Answer: amino acid sequence
Output:
What sequence is the primary structure of a protein?