You have learned that different antibody isotypes activate distinct immune mechanisms. For example, IgE activates mast cells, while IgG activates ADCC. The heavy chain isotypes differ structurally in the constant regions. These structural differences lead to functional differences. What is NOT one of the structural or functional differences between different antibody isotypes

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answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.