V. Discuss classification of types of immunity with examples.

Immunity is the body's ability to resist or fight off diseases and infections. It can be classified into two main types: innate immunity and adaptive immunity.

1. Innate Immunity: This is the natural immunity that a person is born with. It is non-specific and is the first line of defense against pathogens. It includes physical barriers like skin and mucous membranes, and internal defenses like phagocytes and natural killer cells. For example, when you get a cut on your skin, the area becomes inflamed. This is your innate immune system at work, trying to prevent the spread of infection.

2. Adaptive Immunity: This is the immunity that a person develops throughout their life. It is specific and has a memory component, meaning it can "remember" pathogens it has encountered before and respond more quickly and effectively to subsequent encounters. It includes B cells and T cells. For example, if you've had chickenpox once, your adaptive immune system "remembers" the virus and prevents you from getting it again.

Adaptive immunity can be further divided into two types: active immunity and passive immunity.

a. Active Immunity: This is the immunity that develops after exposure to a disease-causing organism or after immunization. It is long-lasting, sometimes lifelong. For example, if you've been vaccinated for measles, you have active immunity against the virus.

b. Passive Immunity: This is the immunity that is "borrowed" from another source and it lasts for a short time. For example, babies have passive immunity passed on from their mothers through the placenta and breast milk.

In summary, the classification of immunity includes innate and adaptive immunity, with adaptive immunity further divided into active and passive immunity. Each type plays a crucial role in protecting the body from diseases and infections.