Question

     In what way does blood assist in immune function?

	A.	Red blood cells transport gases.
	B.	Albumins transport hormones.
	C.	Plasma antibodies and white blood cells defend against pathogens.
	D.	Platelets allow clotting.

What is so special about hemoglobin?

	A.	It is organic and gluten free.
	B.	It reversibly binds O2, i.e. it binds and releases O2 in the pulmonary circulation and systemic tissues, respectively.
	C.	It carries oxygen and moves freely across capillary walls to deliver oxygen and retrieve carbon dioxide from metabolically active tissues.
	D.	It has 34 hydrogen molecules.

3. What does erythropoietin (EPO) do?

		A. It stimulates red blood cell synthesis in the white bone marrow.
		B. It stimulates red blood cell production in the red bone marrow.
		C. It stimulates red blood cell production in the circulating plasma.
		D. It stimulates hematopoiesis.
		E. It stimulates hemolysis.

Answer 1

QUESTION 1

Option 'C' is correct

Justification: White blood cells finds the foreign invaders and pathogens like bacteria, fungi, viruses etc., by moving through the blood and tissues throughout the body and when they finds them, they immediately launches an immune attack. So, white blood cells and plasma antibodies in the blood defend against pathogens, by assisting in immune function.

Justification for incorrect options:

• Option 'A' is incorrect because blood transport gases like oxygen and carbon dioxide but, this transport activity of blood assist in respiratory function but NOT in immune function.
• Option 'B' is incorrect because albumin acts as a carrier protein for transporting hormones and this activity assists in stabilizing the extracellular fluid volume by contributing to the oncotic pressure but will NOT assist in the immune function.
• Option 'D' is incorrect because platelets are involved in coagulation and wound healing by clotting mechanism. This is not responsible for immune function.

QUESTION 2

Option 'C' is correct

Justification: Hemoglobin is a protein in red blood cells which is responsible for carrying oxygen to the tissues and organs of the body and for transporting carbon dioxide from the organs and tissues to the lungs. So, the main function of hemoglobin is to carry oxygen to different organs and tissues in the body and to transport carbon dioxide from the metabolically active tissues and back to the lungs.

Justification for incorrect options:

• Option 'A' is incorrect. Although hemoglobin is organic and gluten free, it is not a special protein for this feature. It's main function is to carry oxygen to different organs and tissues of the body and to transport carbon dioxide from other organs back to the lungs.
• Option 'B' is incorrect because the reversible binding of hemoglobin to oxygen is not a special feature of hemoglobin when compared to its main function (carries oxygen to organs and tissues and transports carbon dioxide from other organs and tissues back to the lungs).
• Option 'D' is incorrect because hemoglobin is not special for having 34 hydrogen molecules.

QUESTION 3

Option 'B' is correct

Justification: Erythropoietin (EPO) is produced by the juxtaglomerular cells in kidney and is responsible for stimulating the production of red blood cells in the red bone marrow.

Justification for incorrect options:

• Option 'A' is incorrect because erythropoietin stimulates the production of red blood cells in the red bone marrow but NOT in the white bone marrow.
• Option 'C' is incorrect because erythropoietin stimulates erythropoiesis but NOT hematopoiesis, as hematopoiesis is the formation of mature blood cells whereas erythropoiesis is the formation of mature RED blood cells (erythrocytes).
• Option 'D' is incorrect because hemolysis occurs when there is a fall in erythropoietin levels but erythropoietin will NOT stimulate hemolysis.

Thank you!