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

Ex Input:
Transpiration is when plant roots absorb liquid water and release water vapor into the atmosphere.

Ex Output:
What is it called when plant roots absorb liquid water and release water vapor into the atmosphere?

Ex Input:
Phospholipids are vesicles made of.

Ex Output:
What are vesicles made of?

Ex Input:
Citric acid is citrate an ionized form of.

Ex Output:
What is citrate an ionized form of?