Chapter 17, Problem 3MCQ

Summary Introduction

Introduction:

The immune system is defined as the group of cells or tissues or organs that functions against the foreign substance to provide the immunity. The immunity is classified into two categories, innate and adaptive. The innate are non-specific defense mechanism, which acts immediately after the exposure of antigens or foreign substances on the body. The adaptive are antigen-specific immunity that adapts the immune system by formation of immune cells or memory cells for specific antigen.

Adaptive immunity acquires either be actively or passively, when person exposed to microorganism or foreign substances. The active and passive acquired immunity cab be obtained by natural or artificial ways. Based on this, the adaptive immunity is categorized into four types.