Given a scientific passage and an answer, generate a question for the given answer.

Example Input: Passage: Eggs are female gametes that form in the ovaries and are released into the fallopian tubes. Answer: eggs
Example Output: What are the female gametes that form in the ovaries?

Example Input: Passage: Structure of the trp operon. The trp operon is composed of 5 structural genes, 1 regulatory gene and other regulatory sequences, including the promoter, operator and leader sequence. Within the leader sequence is the attenuator region. In the presence of tryptophan, the structural genes are not transcribed. Answer: they are not transcribed
Example Output: What happens to structural genes in the presence of tryptophan?

Example Input: Passage: The jointed appendages of arthropods may be used as legs for walking. Being jointed makes them more flexible. Try walking or climbing stairs without bending your knees, and you'll see why joints are helpful. In most arthropods, the appendages on the head have been modified for other functions. Figure below shows some of the head appendages found in arthropods. Sensory organs such as eyes are also found on the head. Answer: walking
Example Output:
What may the jointed appendages of arthropods be used for?