Question

Given below are four statements (i-iv) regarding the human blood circulatory system. Choose the option representing the correct statements.
(i) Arteries are thick-walled and have narrow lumen as compared to veins
(ii) WBCs play a very important role in blood clotting
(iii) Persons with blood group AB can donate blood to any person with any blood group under the ABO system
(iv) In diseases such as dengue platelet count decreases to a great extent

• A. (i) and (iv)
• B. (i) and (ii)
• C. (ii) and (iii)
• D. (iii) and (iv)

Answer 1

The correct option is A

(i) and (iv)

Arteries are thick-walled and have narrow lumen as compared to veins.
In diseases such as dengue platelet count decreases to a great extent
AB blood group person have both antigens A and B, so will be having both anti-A and anti-B antibodies in the plasma. Due to the presence of both antibodies against antigen A and B, a person with AB blood group cannot donate blood to anyone except AB recipients. But the AB blood group is a universal recipient.
Platelets play an important role in blood clotting.