Question

Oxygen is transported through blood mainly by
(a)Leucocytes
(b)Erythrocytes
(c)Thrombocytes
(d)Blood plasma

Answer 1

Hint: Oxygen is transported through blood mainly through certain corpuscles present in the blood. They are red-colored cells that lack mitochondria and carry out anaerobic respiration. They are rich in hemoglobin, which is an iron-containing molecule.

Complete Answer:
Oxygen is transported from the lungs to the different parts of the body through blood. This is mainly done by certain iron-containing red-colored cells known as Red Blood Corpuscles(RBCs) or Erythrocytes.
They carry out the function of gaseous exchange, by transporting carbon dioxide from different parts of the body to the lungs and carrying oxygen back from the lungs to the different tissues and organs.

Additional Information:
- In human blood, the mature red blood cells are flexible and have an oval-biconcave structure. They lack the nucleus and most other organelles, to accommodate the maximum amount of hemoglobin and thus oxygen. They lack mitochondria too, and hence they respire anaerobically.
-They are produced in the red bone marrow present at the ends of long bones. They have a lifespan of approximately 120 days.
-They are the chief cells for oxygen transport and gaseous exchange in almost all the vertebrates.
-RBCs also contribute to the viscosity of blood and color of the blood due to their abundance.

So, the correct answer is, “Erythrocytes”

Note:
-Crocodile icefish is a vertebrate that lives in oxygen-rich cold water and they dissolve the oxygen freely in their blood. Because of this trait, they lack erythrocytes for oxygen transport.
-Certain mammals like camels have RBCs which retain their nucleus even after maturation.
-Sickle cell anemia is a condition in which the erythrocytes take a sickle shape instead of the usual bi-concave shape in hypoxic conditions, which lead to occlusion of blood vessels and prove fatal. As such, the oxygen-carrying capacity is also reduced in this condition due to lesser hemoglobin.