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

[EX Q]: Passage: Heat waves have increased in frequency and duration in recent years. The summer 2011 North American heat wave brought record temperatures across the Midwestern and Eastern United States. Many states and localities broke records for temperature and for the most days above 100 o F. Answer: cell membrane
[EX A]: What are all cells surrounded by?

[EX Q]: Passage: Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell, as shown in Figure below . Exocytosis occurs when a cell produces substances for export, such as a protein, or when the cell is getting rid of a waste product or a toxin. Newly made membrane proteins and membrane lipids are moved to the plasma membrane by exocytosis. Answer: exocytosis
[EX A]: What describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell?

[EX Q]: Passage: Some of the most interesting evidence for evolution comes from vestigial structures . These are body parts that are no longer used but are still present in modern organisms. Examples in humans include tail bones and the appendix. Answer: vestigial structure
[EX A]:
What is the tail bone an example of?