Immune Defence: Part 2

The video explains how the immune system builds resistance to diseases through the production of antibodies. Pathogens produce antigens that lymphocytes recognize, triggering an immune response. Lymphocytes replicate and produce antibodies that tag pathogens for destruction. Some lymphocytes remain as memory cells, enabling a faster response to future infections. This process underlies the concept of immunity and the effectiveness of vaccinations.

What is the role of antigens in the immune system?

• They are cells that ingest pathogens.

• They destroy pathogens directly.

• They are proteins that mark foreign cells.

• They are specific chemicals produced by pathogens.

How do antibodies assist in fighting off pathogens?

• By directly ingesting pathogens.

• By marking foreign cells for destruction.

• By producing more lymphocytes.

• By creating new antigens.

What happens to lymphocytes after they first produce a specific antibody?

• They become inactive and stop functioning.

• They remain in the immune system for future responses.

• They transform into antigens.

• They are destroyed by the immune system.

Why is the body's response quicker during subsequent infections?

• The immune system becomes weaker.

• The pathogens become less harmful.

• Lymphocytes remember the pathogen and respond faster.

• The body produces new antigens.

What is the principle behind vaccinations?

• They introduce new pathogens to the body.

• They weaken the immune system temporarily.

• They prepare the immune system for future infections.

• They eliminate all antigens from the body.