3.2 The Body's Defence

Question 1

What is the first line of defense against pathogens?

Answer 1

Skin, mucous membranes, and bodily fluids (e.g., tears, saliva)

Question 2

How do white blood cells defend the body?

Answer 2

By phagocytosis (engulfing pathogens), producing antibodies, and releasing antitoxins

Question 3

What is an antibody?

Answer 3

A protein produced by white blood cells that targets and neutralizes specific pathogens

Question 4

What is phagocytosis?

Answer 4

The process by which white blood cells engulf and digest pathogens

Question 5

What are antitoxins?

Answer 5

Substances produced by white blood cells that neutralize toxins produced by pathogens

Question 6

How do vaccines help the immune system?

Answer 6

By introducing harmless antigens to stimulate an immune response and produce memory cells

Question 7

What is active immunity?

Answer 7

Immunity produced by the body in response to exposure to a pathogen or a vaccine

Question 8

What is passive immunity?

Answer 8

Immunity gained by receiving antibodies from another person or animal, such as through breast milk or antibody injections

Question 9

What is the purpose of a booster vaccine?

Answer 9

To maintain immunity by stimulating the immune system to produce more memory cells

Question 10

What is herd immunity?

Answer 10

When a large portion of the population is immune to a disease, reducing its spread