Answer:
Water evaporates and ends up in clouds high up in the atmosphere. Since it is colder in the upper atmosphere, the clouds condense.
This might have been the cause of not being exposed to this specific pollen during his years in Chicago. Allergic reactions can develop when the stimuli presented even when its not contagious causes the immune system to trigger and act in a defensive stance. This delayed effect may have been the cause of the sudden expression of the immune system.
I-what? The only thing I could think of is Parents?
1. molecul of DNA 2. dna packed (coild) around histon h1 3.second stage of dna packing -solenoid thread 4. third stage of packing-chromosomal thread 5.chromosome-chromosomal threads are packed inside