Sponsor Area

Principles Of Inheritance And Variation

Question
CBSEENBI12046926

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

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

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.

Solution

C.

If assertion is true but reason is false

Haemophilia, also called bleeder's disease is a X-linked recessive disorder. The person which contains the recessive gene for haemophilia lacks a normal clotting substance (thromboplastin) in blood. So minor injuries cause continuous bleeding and ultimate death of the person due to hemorrhages.

Haemophilia is of two types : type A characterized by lack of antihaemophilic globulin (factor VIII) and type B characterized by a defect in plasma thromboplastic component (factor IX).
Prothrombin is an inactive plasma protein and is produced by liver. It helps in blood clotting. It is not produced by platelets.