Question

Which statement correctly describes the immune response?

The third line of defense involves the action of specialized cells.

The first line of defense is intact skin.

The second line of defense involves the immune system recognizing foreign invaders.

All of the above are correct.

Answer 1

The correct statement that describes the immune response is that the third line of defense involves specialized cells, the first line of defense is intact skin, and the second line includes the immune system recognizing foreign invaders, so 'all of the above are correct.'

Step-by-step explanation:

The immune response can be categorized into three levels of defense against pathogens:

• The first line of defense includes barrier defenses such as intact skin and mucous membranes, which act instantaneously to prevent pathogenic invasion.
• The second line of defense attacks pathogens that manage to enter the body and includes the inflammatory response and phagocytosis by nonspecific leukocytes as a part of the innate immune response.
• The third line of defense involves the lymphatic system and it is a specific immune response that is activated when pathogens bypass the first two lines. This response involves B and T cells, which are specialized cells that are key in targeting specific pathogens.

Therefore, the correct statement that describes the immune response is that 'all of the above are correct,' including the action of specialized cells, the role of intact skin, and the immune system recognizing foreign invaders as part of the bodies' defense mechanisms.

Answer 2

The statement which correctly describes the immune response is the third line of defense involves the action of specialized cells.

The third one is the specific resistance which relies on antigens found in foreign microbes. These antigens are proteins or special substances that serve as the stimulus to produce an immune response.