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

[EX Q]: Oxygen is transferred through capillaries.
[EX A]: Which blood vessels is oxygen transferred through?

[EX Q]: Protist diseases in humans are caused by protozoa.
[EX A]: What type of diseases in humans are caused by protozoa?

[EX Q]: After fertilization, a zygote forms into two cells.
[EX A]:
After fertilization, how many cells does a zygote form into?