instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Ionic compounds contain cations and anions rather than discrete neutral molecules.
answer:
Ionic compounds contain cations and anions rather than what?


question:
Biodiversity is the term for the measurement of the amount of variation of species in a given area.
answer:
What is the term for the measurement of the amount of variation of species in a given area?


question:
They are not transcribed happens to structural genes in the presence of tryptophan.
answer:

What happens to structural genes in the presence of tryptophan?