Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[EX Q]: Darwin believed in gradualism.
[EX A]: Did darwin believe in punctuated equilibrium or gradualism?

[EX Q]: Nonvascular plants are the only plants with a life cycle in which the gametophyte generation is dominant.
[EX A]: What are the only plants with a life cycle in which the gametophyte generation is dominant?

[EX Q]: Mucosal tissues are major barriers to the entry of pathogens into the body.
[EX A]:
What type of tissues are major barriers to the entry of pathogens into the body?