Active immunity means

Options

A. A.Resistance developed after disease
B. B.Resistance developed before disease
C. C.Increasing rate of heart beat
D. D.Increasing quantity of blood

Answer

**Step-by-Step Solution:**

1. **Definition of Active Immunity**: Active immunity refers to the immunity that develops when an individual's own immune system produces antibodies in response to a pathogen or a vaccine.

2. **Mechanism of Development**: This type of immunity can be acquired through:
- **Natural Infection**: When a person is exposed to a disease-causing agent (pathogen), their immune system responds by creating specific antibodies against that pathogen.
- **Vaccination**: Vaccines contain weakened or inactive parts of a pathogen, which stimulate the immune system to produce antibodies without causing the disease.

3. **Duration of Active Immunity**: Active immunity is usually long-lasting, as the immune system retains a memory of the pathogen, allowing for a quicker response upon future exposures.

4. **Comparison with Passive Immunity**: Unlike active immunity, passive immunity is provided when a person receives antibodies from another source (e.g., a mother to her baby through breast milk or placenta). This does not involve the individual's immune system producing its own antibodies.

5. **Conclusion**: Therefore, active immunity means the resistance developed after exposure to a disease or vaccination.

**Final Answer**: Active immunity means the resistance developed after disease or vaccination.

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