Chapter 33, Problem 1TC

Summary Introduction

To determine:

The advantages and disadvantages of having only innate immunity in primitive organism such as invertebrates that lacks more specific antibody and cell mediated immunity.

Introduction:

The immune system of an organism provides the defense mechanism to fight against the foreign invaders including bacteria, viruses, and other toxins. The living organisms possess two types of immunity which includes: innate immune response and adaptive immune response. Innate immunity develops naturally in an organism and it is a non-specific type of immunity.

Explanation of Solution

The primitive organisms such as invertebrates possess the components and mechanism of innate immunity, their body lacks lymphocytes and thus lacks an adaptive immune system. The evolution process in the organism results in the formation of more complex immune system. Vertebrates are the first who gained the most complex immune system.

The advantage of having only innate immune system to the organism that lack an adaptive immune system is that the innate immunity provides protection against a wider range of pathogens such as bacteria, viruses and environmental toxins, which they experienced commonly. The innate immune responses are expressed very fast and thus they are important for the survival of organism.

The disadvantages of having only innate immune system are that the organism is not able to respond to a specific antigen. The innate immune system also lacks a memory component which results in continuous exposure of the same antigen. The innate immune immunity includes a non specific immune response. It will not respond to a novel antigen and makes the entire population at risk. It is not able to produce antibodies as it lacks lymphocytes.

Conclusion

The innate immunity has advantages as well as disadvantages in the organism that do not possess adaptive immune responses. The innate immunity comes naturally and protects the organism from bacterial infection, viral infection and other toxins present in environment.