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.
Explanation: The cytoskeleton is composed of at last three different types of fibers: microtubules, microfilaments, and intermediate filaments. These fibers are distinguished by their size with microtubules being the thickest and microfilaments being the thinnest.
The differences between osmosis and diffusion it that diffusion refers to the movement of any chemical from one place to another, whereas osmosis exclusively refers to the movement of water across the semipermeable membrane. (cell membrane)