AIIMS 2005 Zoology Genetic Disorders Assertion Reason Question

To tackle the question regarding haemophilia, let's break it down into the assertion and the reason given.

Assertion

"Persons suffering from haemophilia fail to produce blood clotting factor VIII."

Explanation: Haemophilia is a genetic disorder that primarily affects the blood's ability to clot. It is commonly caused by mutations in the gene that encodes for clotting factor VIII, which is essential for the formation of blood clots. Individuals with haemophilia A, the most common type, have a deficiency or absence of factor VIII, leading to prolonged bleeding and difficulty in clot formation. This assertion is true.

Reason

"Prothrombin producing platelets in such persons are found in very low concentration."

Explanation: Prothrombin is a precursor to thrombin, an enzyme crucial for blood coagulation. It is produced in the liver and is not directly related to platelet concentration. In individuals with haemophilia, the primary issue is the lack of factor VIII, not a deficiency in prothrombin or platelets. In fact, platelet counts in haemophilia patients are usually normal. Therefore, this statement is false.

Conclusion on Options

Given the analysis:

1. Assertion is true: Persons suffering from haemophilia do indeed fail to produce sufficient blood clotting factor VIII.
2. Reason is false: The statement about prothrombin production and platelet concentration in haemophilia is incorrect.

Correct Answer: C

Thus, the correct answer is C) If Assertion is true statement but Reason is false.

Clarification of Other Options:

• A) This option is incorrect because although the assertion is true, the reason is false.
• B) This option is also incorrect for the same reason; the reason fails to provide a correct explanation for the assertion.
• D) This option is incorrect because the assertion is true, meaning both statements cannot be false.

Summary

In summary, the assertion accurately describes a key feature of haemophilia, while the reason incorrectly describes the relationship between platelets and prothrombin. Thus, the answer is clearly option C. Understanding the roles of various clotting factors and their interactions is crucial in studying conditions like haemophilia.