Chapter 29, Problem 1MCQ

Summary Introduction

Introduction:

Many organisms attack other organisms and cause infectious diseases. These are known as pathogens. However, the body contains a well-defined organ system that fights with the pathogen. This protective organ system is termed as the immune system. The major function of the immune system is to fight against the invading pathogens.

Answer to Problem 1MCQ

Correct answer:

Lymph is a major component of the lymphatic system. It originates from plasma and moves from the circulatory system with the help of blood vessels. Hence, the correct answer is option b.

Explanation of Solution

Reason for correct answer:

Option b. is given as, “plasma that leaks out of blood vessels.”

The organ system that collects all the leaked body fluids and helps in the destruction of pathogens is termed as the lymphatic system. Lymph is a vital fluid of this system. It originates from the blood plasma and moves out of the circulatory system through the blood vessels. After this, the lymph collects all the invading pathogens and gets absorbed by the lymphatic vessels. In this way, the pathogens are attacked by the lymphatic system.

Reason for incorrect answer:

Option a. is given as, “Blood that contains important pathogens.”

Lymph is a fluid that originates from the plasma present in the blood. It moves out of the circulatory system through the blood vessels. After this, the lymph collects all the invading pathogens and gets absorbed by the lymphatic vessels. In this way, the pathogens are attacked by the lymphatic system. However, lymph is not blood. Hence, option a. is incorrect.

Option c. is given as, “Any part of the body that contains immune cells.”

Lymph is a vital fluid of the lymphatic system. It originates from the blood plasma and moves out of the circulatory system through the blood vessels. After this, the lymph collects all the invading pathogens and gets absorbed by the lymphatic vessels. However, it does not contains any immune cells. Hence, option c. is incorrect.

Option d. is given as, “Pathogen-catching fluid produced at the spleen.”

Lymph originates from the blood plasma and moves out of the circulatory system through the blood vessels. Spleen is not responsible for the production of lymph. After this, the lymph collects all the invading pathogens and gets absorbed by the lymphatic vessels. In this way, the pathogens are attacked by the lymphatic system. Hence, option d. is incorrect.

Hence, the options a., c., and d. are incorrect.

Conclusion

Lymph is a type of blood plasma that helps in the destruction of attacking pathogens and protects the body from infectious diseases. Thus, the correct option is b.