instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Photography by Kat. Ferns are common in the understory of the tropical rainforest . CC BY 2.0. Answer: understory
answer:
In a tropical rainforest, where are ferns common?

question:
Passage: Another barrier is the saliva in the mouth, which is rich in lysozymean enzyme that destroys bacteria by digesting their cell walls. The acidic environment of the stomach, which is fatal to many pathogens, is also a barrier. Additionally, the mucus layer of the gastrointestinal tract, respiratory tract, reproductive tract, eyes, ears, and nose traps both microbes and debris, and facilitates their removal. In the case of the upper respiratory tract, ciliated epithelial cells move potentially contaminated mucus upwards to the mouth, where it is then swallowed into the digestive tract, ending up in the harsh acidic environment of the stomach. Considering how often you breathe compared to how often you eat or perform other activities that expose you to pathogens, it is not surprising that multiple barrier mechanisms have evolved to work in concert to protect this vital area. Answer: by digesting their cell walls
answer:
How does lysozyme destroy bacteria?

question:
Passage: Are you on the basketball team? Are you a cheerleader? Do you play an instrument in the band? Your niche would be your role or place in the school. Organisms also each have their own niche in the ecosystem. Is an organism a producer or a consumer? How does the organism interact with other organisms? Is the organism involved in any symbiotic relationships?. Answer: niche
answer:
An organism's unique role in the ecosystem is called its what?