Final answer:
Histamine is the chemical released by mast cells and basophils that causes various inflammatory and allergic responses including vasodilation, increased capillary permeability, and bronchoconstriction.
Step-by-step explanation:
The chemical that is a product of mast cells and basophils and is responsible for causing vasodilation, capillary permeability, bronchoconstriction, and contraction of the gut is histamine. When a mast cell is irritated or damaged, it releases histamine, which contributes to the inflammatory response by causing swelling, redness, and itching. Histamine plays a significant role in allergic reactions, leading to symptoms such as runny nose, watery eyes, and in more severe cases, can cause bronchiole constriction resulting in difficulty breathing and coughing.