instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
The majority of human genes have two or more possible alleles.
answer:
How many possible alleles do the majority of human genes have?

question:
The right atrium of the heart receives the blood is pumped from veins of the systemic circuit.
answer:
What part of the heart receives the blood is pumped from veins of the systemic circuit?

question:
Oxygen is transferred through capillaries.
answer:
Which blood vessels is oxygen transferred through?