Question

1. what is immunity?

a. the ability to fight pathogens
b. the ability to breathe
c. the ability to digest food
d. the ability to produce antibodies

1. how does skin protect the body from pathogens?

a. by producing antibodies
b. by trapping pathogens
c. by keeping pathogens out and destroying them with sweat and oil
d. by digesting pathogens

1. what is the purpose of a vaccine?

a. to kill bacteria in the stomach
b. to weaken the immune system
c. to introduce a weakened pathogen to strengthen immunity
d. to cause sickness

1. what type of white blood cell destroys pathogens during the inflammatory response?

a. t - cell
b. b - cell
c. phagocyte
d. antibody

1. what do t - cells do in the immune response?

a. identify markers on foreign cells
b. trap pathogens
c. produce antibodies
d. kill bacteria with acid

Explanation:

1. Immunity refers to the body's ability to fight off pathogens. Option A is correct as it directly relates to the concept of immunity. Option B (breathing ability) and C (digestive ability) are unrelated to immunity. Option D (producing antibodies) is a part of the immune response but not the full definition of immunity.
2. Skin acts as a physical barrier, keeping pathogens out. Sweat and oil on the skin have antimicrobial properties that can destroy pathogens. Option C is correct. Option A (producing antibodies) is done by B - cells. Option B (trapping pathogens) is more of a function of mucus membranes in some cases. Option D (digesting pathogens) is not a primary function of the skin.
3. Vaccines work by introducing a weakened or inactivated pathogen. This exposure allows the immune system to recognize the pathogen and strengthen immunity. Option C is correct. Option A (killing stomach bacteria) is not the purpose of vaccines. Option B (weakening the immune system) is incorrect. Option D (causing sickness) is not the intended purpose (though sometimes mild symptoms can occur as the immune system responds).
4. Phagocytes are white blood cells that engulf and destroy pathogens during the inflammatory response. Option C is correct. T - cells (Option A) are involved in cell - mediated immunity. B - cells (Option B) produce antibodies. Antibodies (Option D) are proteins, not white blood cells.
5. T - cells identify markers (antigens) on foreign cells. Option A is correct. Trapping pathogens (Option B) is not a main function of T - cells. Producing antibodies (Option C) is done by B - cells. Killing bacteria with acid (Option D) is not a T - cell function.

Answer:

1. A. The ability to fight pathogens
2. C. By keeping pathogens out and destroying them with sweat and oil
3. C. To introduce a weakened pathogen to strengthen immunity
4. C. Phagocyte
5. A. Identify markers on foreign cells