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

Input: Consider Input: Humans have 23 pairs pairs of chromosomes.

Output: How many pairs of chromosomes do human have ?

Input: Consider Input: The bird ancestor that lived in trees developed wings, which is commonly associated with birds.

Output: The bird ancestor that lived in trees developed what feature commonly associated with birds?

Input: Consider Input: Rna analysis type of analysis is performed to study gene expression patterns in cells.
Output: What type of analysis is performed to study gene expression patterns in cells?