The microorganisms which cause diseases in humans, animals, and plants are known as pathogens. Bacteria, Viruses, Fungi, Protozoan, and Helminthes are different types of microorganisms that cause infectious diseases.

Differentiate between active and passive immunity.

Vaccination: Immunisation programs help prevent infectious diseases by building immunity in populations.
Hygiene and Sanitation: Promoting clean water, proper sanitation, and good personal hygiene reduces the spread of waterborne and food borne diseases.
Vector Control: Managing disease-carrying vectors, such as mosquitoes, is crucial for preventing vector-borne illnesses.

Features Active Immunity Passive Immunity Definition Active immunity is developed by the antibodies that are produced by one's own immune cells in response to a foreign pathogen or vaccine. Passive immunity is developed by introducing preformed antibodies into the host body. Duration The developed immunity remains in the body for a lifetime. Example: A person who recovered from measles develops immune cells that will remain active for the rest of the patient's life. The immunity remains in the body for a temporary period. Example: The mother's colostrum rich in IgA provides passive immunity. Features Active Immunity Passive Immunity Response This immunity takes some time to develop. This immunity develops immediately. Memory This type involves primary and secondary immune response, where antibodies are produced from plasma and memory cells. It doesn't develop any immunological memory.