Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: Some bacteria depend on a host organism for energy and nutrients. These bacteria are known as parasites . If the host starts attacking the parasitic bacteria, the bacteria release a layer of slime that surrounds the cell wall. This slime offers an extra layer of protection. Answer: layer of slime
Solution:
When a host attacks a parasitic bacteria, the bacteria release what to surround the cell wall?