Chapter 13, Problem 2Q

Summary Introduction

To determine:

Whether the nonspecific or the specific arms of the immune response evolved first in mammals.

Concept introduction:

The body mechanisms that protect against infections are innate defense and adaptive defense. Innate is a nonspecific type of defense which develops quickly. It provides general response regardless of pathogen type and exposure numbers. Adaptive defense is the precise mechanism (specific) that targets a specific pathogen. The response of the adaptive immunity is carried by the lymphocytes.