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

Input: Consider Input: The double helix dna shape forms when the two nucleotide chains wrap around the same axis.

Output: What distinctive dna shape forms when the two nucleotide chains wrap around the same axis?

Input: Consider Input: The action of flushing the toilet, performed multiple times daily, is the single biggest use of water in the home.

Output: What action, performed multiple times daily, is the single biggest use of water in the home?

Input: Consider Input: A(n) arachnid has additional appendages called the chelicerae and the pedipalps.
Output: What class of invertebrate animals has additional appendages called the chelicerae and the pedipalps?