What is immunity? Explain natural and acquired immunity.
Answer:
Immunity means the resistance of the body to a disease. It is due to the presence of antibodies in our body against the disease-causing microorganisms known as antigens. When these antigens enter our body, antibodies are formed which prevent the disease.
Natural immunity means that a person has these antibodies since birth, e.g., whenever antigens, say of cholera enter the body, the person will not suffer from the disease.
Acquired immunity means when a person suffers from a disease once, antibodies for these particular disease-causing antigens will be formed in the body and he will not get the same disease again.