Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Human immunodeficiency virus (HIV) infections affecting WBCs is a cause of Acquired immunodeficiency syndrome (AIDS) and death
Reason (R) : The disease causing intrinsic factors are present within the body of host such as malfunctioning of immune system resulting in immunodeficiency disease and host may die due to secondary bacterial infection
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

To differentiate:
- Extrinsic factors are external (viruses, bacteria, toxins, trauma).
- Intrinsic factors are internal (genetics, auto-immune issues, metabolic errors).
Since HIV is an external virus, it is an extrinsic cause, so the general definition of intrinsic factors in (R) cannot be the explanation for (A).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Diseases are caused by a combination of intrinsic (internal) and extrinsic (external) factors.
Intrinsic factors originate from within the host, such as genetic mutations, immune system malfunctions, or age-related changes.
Extrinsic factors are external agents, such as physical injuries, toxins, or infectious pathogens (like viruses).

Step 2: Detailed Explanation:
Let us evaluate the Assertion and the Reason.
Assertion (A) is correct. The Human Immunodeficiency Virus (HIV) targets and infects white blood cells, specifically CD4+ T helper cells.
This leads to progressive depletion of these cells, causing Acquired Immunodeficiency Syndrome (AIDS).
Without effective cellular immunity, the host becomes highly susceptible to opportunistic secondary infections and malignancies, eventually leading to death.
Reason (R) is also correct. In general pathology, intrinsic factors of disease are those originating from within the host, such as an inherited or acquired malfunction of the immune system.
When the immune system fails to function properly, the animal or human host can suffer from immunodeficiency, and death often results from secondary bacterial or viral infections.
Let us analyze the relationship between the two statements.
HIV-induced AIDS is initiated by an extrinsic factor (the virus HIV itself), which is an external biological agent.
While the *result* of HIV infection is an immunodeficiency state, the primary cause of the disease is extrinsic, not intrinsic.
The Reason (R) defines and describes intrinsic disease-causing factors.
Therefore, although both statements are true descriptions of pathological concepts, the Reason (R) does not explain the Assertion (A).
Thus, both (A) and (R) are true, but (R) is NOT the correct explanation of (A).

Step 3: Final Answer:
The correct option is (B).