Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Human Health and Disease

Question:

Read the passage and answer the question given below.

When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation or infectious organisms gaining access into body during natural infection induce active immunity. When antibodies are directly given to protect the body against foreign agents, it is called passive immunity.

Match List I with List II:

List I List II
A. Physical Barrier I. Saliva
B. Cellular Barrier II. Interferons
C. Physiological Barrier III. Skin
D. Cytokine Barrier IV.  Polymorpho-nuclear leukocytes

 Choose the correct answer from the options given below:

Options:

A-III, B-I, C-II, D-IV

A-III, B-IV, C-I, D-II

A-I, B-IV, C-III, D-II

A-IV, B-I, C-III, D-II

Correct Answer:

A-III, B-IV, C-I, D-II

Explanation:

The correct answer is Option (2)-A-III, B-IV, C-I, D-II

List I List II
A. Physical Barrier III. Skin
B. Cellular Barrier IV.  Polymorpho-nuclear leukocytes
C. Physiological Barrier I. Saliva
D. Cytokine Barrier II. Interferons

Innate immunity is a non-specific defense mechanism that is present in an individual from birth. It consists of various types of barriers designed to prevent the entry of foreign agents into the body. Innate immunity encompasses four main categories of barriers:

(i) Physical Barriers: The skin serves as the primary physical barrier, effectively preventing the entry of microorganisms. Additionally, mucus coats the epithelium lining the respiratory, gastrointestinal, and urogenital tracts, aiding in the capture and entrapment of microbes attempting to enter our body.

(ii) Physiological Barriers: Various physiological factors act as barriers to microbial growth. These include the acidic environment in the stomach, saliva in the mouth, and tears produced by the eyes, all of which deter the proliferation of microbes.

(iii) Cellular Barriers: The immune system deploys certain types of white blood cells, such as polymorphonuclear leukocytes (PMNL-neutrophils), monocytes, natural killer cells (a type of lymphocyte) in the bloodstream, and macrophages in tissues. These cells have the ability to phagocytose (engulf and destroy) microbes, providing an essential defense mechanism against invading pathogens.

(iv) Cytokine Barriers: In response to viral infections, infected cells release proteins called interferons. These interferons play a vital role in protecting non-infected cells from further viral infections, acting as a crucial part of the innate immune response.

To summarize, innate immunity consists of multiple layers of defense mechanisms, including physical, physiological, cellular, and cytokine barriers, all of which collectively serve to protect the body from foreign invaders.