Question

Write a note on immunity.

Hint:

A strong immune system is essential for health, and vaccines help enhance immunity against specific diseases.

Answer 1

Step 1: Definition of Immunity.
Immunity is the ability of an organism to resist or defend against infections or diseases. It is achieved through the body’s immune system, which identifies and destroys pathogens such as bacteria, viruses, and other harmful microorganisms.
Step 2: Types of Immunity.
1. Innate Immunity: The first line of defense, which is nonspecific and includes barriers like skin, mucous membranes, and the immune cells (phagocytes). 2. Adaptive Immunity: A more specific response that develops over time, involving lymphocytes (B cells and T cells) that remember pathogens for faster responses in the future.
Step 3: Importance of Immunity.
Immunity plays a critical role in preventing infections, diseases, and cancers. Vaccines, for example, help train the immune system to recognize and fight specific pathogens.
Step 4: Conclusion.
The immune system is essential for maintaining health and protecting against harmful agents in the environment.
Final Answer: \[ \boxed{\text{Immunity is the ability of an organism to resist and fight off infections.}} \]