Question

1. last week, amello was walking to class when he tripped, fell, and scraped his knee. while sitting in his next period class amello noticed that his knee felt hot and appeared red and puffy. amello remembered learning in science class that increased temperature and swelling at the site of an injury is an indication of one of our bodys immune responses. what line of defense is working to protect amello from possible pathogens? a. the circulatory system. b. the 3rd line of defense, immune response. c. the 1st line of defense, barriers to infection. d. the 2nd line of defense, inflammatory response.

Explanation:

The first line of defense includes physical and chemical barriers like skin. The second line of defense is the inflammatory response (symptoms like redness, swelling, heat). The third line is the immune response with specific immunity. Since the question is about the body's defense mechanism related to injury (symptoms of inflammation), we check each option.

• Option A: The circulatory system is not a line of defense.
• Option B: The third - line (immune response) is specific and comes after the second - line.
• Option C: The first - line (barriers) is not related to the inflammatory symptoms.
• Option D: Inflammation (redness, swelling, heat) is part of the second - line of defense.

Answer:

D. The 2nd line of defense, inflammatory response.