ANATOMY

Detailed explanation-1: -Neutrophils. They kill and digest bacteria and fungi. They are the most numerous type of white blood cell and your first line of defense when infection strikes.

Detailed explanation-2: -Answer and Explanation: Fever is not the first line of defense; it is considered the second line of defense. Suppose the first line of defense couldn’t protect the body, and the pathogen still enters the body. In that case, the second line of defense protects the body, including fever, inflammation, and phagocytosis.

Detailed explanation-3: -Physical barrier The innate immune system provides the first line of defense, which is divided broadly into two categories – physical/chemical barriers and nonspecific resistance.