TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Humans have 23 pairs pairs of chromosomes.

SOLUTION: How many pairs of chromosomes do human have ?

PROBLEM: Metabolism produces waste energy in the form of heat, which helps warm-blooded (endotherm) animals conserve and maintain heat at a relatively constant body temperature.

SOLUTION: Metabolism produces waste energy in the form of heat, which helps what type of animal conserve and maintain heat at a relatively constant body temperature?

PROBLEM: Sickle-cell disease significantly impairs the function of circulatory system.

SOLUTION:
Sickle-cell disease significantly impairs the function of what?