Read the following statements :

Statement I: Excessive release of chemicals like histamine by mast cells in humans can cause allergic reactions.

Statement II: When allergens enter the human body, they trigger the activation of mast cells.

Both statement I and statement II  are correct.

The correct answer is Option (3) - Both statement I and statement II  are correct.

Statement I: Excessive release of chemicals like histamine by mast cells in humans can cause allergic reactions.

Explanation: Mast cells are a type of immune cells that play a crucial role in the body's immune response. When mast cells are exposed to allergens, such as pollen or certain foods, they can release chemicals like histamine. Histamine is known to cause various allergic symptoms, including itching, sneezing, runny nose, and skin rashes. The excessive release of histamine and other chemicals by mast cells contributes to the development of allergic reactions.

Statement II: When allergens enter the human body, they trigger the activation of mast cells.

Explanation: Allergens are substances that can trigger an allergic response in susceptible individuals. When allergens enter the human body through inhalation, ingestion, or skin contact, they interact with specific antibodies called immunoglobulin E (IgE) antibodies. These allergen-specific IgE antibodies bind to mast cells, sensitizing them to the particular allergen. Upon subsequent exposure to the same allergen, the allergen binds to the IgE antibodies on the surface of mast cells, leading to their activation and subsequent release of inflammatory chemicals, including histamine. This activation of mast cells by allergens is an important step in the development of allergic reactions.