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

Example Input: Passage: boundary between air masses that is stalled in one place. Answer: aids
Example Output: Opportunistic diseases are usually the direct cause of death of people with what disease?

Example Input: Passage: During meiosis, homologous chromosomes separate and go to different gametes. Thus, the two alleles for each gene also go to different gametes. At the same time, different chromosomes assort independently. As a result, alleles for different genes assort independently as well. In these ways, alleles are shuffled and recombined in each parent's gametes. Answer: during meiosis
Example Output: When do homologous chromosomes separate and go to different gametes?

Example Input: Passage: The Fujita scale measures tornado intensity based on wind speed and damage. Answer: tornado
Example Output:
The fujita scale measures the intensity of what weather event, based on wind speed and damage?