Question

Erythropoiesis is assisted by
(a) ${ Mg }^{ +2 }$
(b) ${ Ca }^{ +2 }$
(c) ${ Cu }^{ +2 }$
(d) ${ Fe }^{ +2 }$

Answer 1

Hint: The element which assists erythropoiesis is the most common element on Earth by mass. It is the fourth most common element found in the earth's crust. In living organisms, it also participates in oxygen transport, DNA synthesis and electron transport.

Complete answer:
Erythropoiesis is assisted by iron in the form of ferrous ions ( ${ Fe }^{ +2 }$). The process of origin, development and maturation of erythrocytes is called ‘erythropoiesis’. Factors necessary for erythropoiesis are stimulating factors, maturation factors and the factors necessary for haemoglobin formation.
Stimulating factors:
- Reduced availability of oxygen to the tissues. It is the most important stimulating factor for erythropoiesis.
- A hormone secreted mainly by the kidney called erythropoietin.
- Thyroxine secreted by the thyroid gland.
- Vitamin A, B, C, D and E.
Maturation factors:
- Vitamin B12 also called cyanocobalamin.
- Castle’s intrinsic factor from the stomach.
- Folic acid.
Factors necessary for haemoglobin formation:
- Proteins and amino acids.
- Minerals like iron, cobalt and nickel.
- Vitamin C, vitamin B2, B3 and B6.
Site of erythropoiesis: In fetal life, it varies from yolk sac, liver, spleen and red bone marrow during different consequent stages of development. After birth till the age of 20 years, RBCs are formed in the red bone marrow and thereafter, from all membranous bones and the end of long bones.
So, the correct answer is, ‘${ Fe }^{ +2 }$.’

Note:
- The process of origin, development and maturation of all the blood cells is called ‘hematopoiesis.’
- Reduced availability of oxygen to the tissues is called hypoxia.
- Erythropoietin is also secreted in small quantities by the liver and the brain.
- The yolk sac is an extra- embryonic membranous structure. It is responsible for preliminary circulation and distribution of nutrients.