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

[EX Q]: Ribosomes are the only organelles that prokaryotic cells have.
[EX A]: What are the only organelles that prokaryotic cells have?

[EX Q]: A pregnant woman should avoid toxic substances while pregnant.
[EX A]: What should a pregnant woman avoid while pregnant?

[EX Q]: Vascular tissue allowed these plants to grow taller.
[EX A]:
Vascular tissue allowed these plants to do what?