Pollen can generate an immune response which is known as hypersensitivity. Hypersensitivity is an uncontrolled and unregulated immune response. Pollen generates IgE mediated type I hypersensitivity which causes acute inflammation in the body which ultimately result in wheals and flares on the skin. It causes hyper activation of mast cells and basophils which cause vasodilation by releasing molecules like leukotrienes, serotonin and prostaglandins. Asthama and atropic dermatitis are the two diseases which occur due to pollen allergies.
I'd say C. an allergic reaction. Mainly because lots of people are allergic to many things and many people intend to have seasonal allergies cause by plants. Hope it helps!
Human skin color is a polygenic trait. That means that it is influenced by many genes. It is known few hundreds of genetic loci that are involved in the determination of skin color.
A theory of evolution that states that a species evolves in spurts of rapid change and then goes through periods of no change is known as <span>punctuated equilibrium.</span>
