Question

The mature cells in the mammalian body, i.e., RBC loses their capacity for
A. Aerobic respiration
B. DNA replication
C. RNA synthesis
D. All of the above

Answer 1

Hint: Red blood cells or red blood corpuscles or RBCs are also termed as erythrocytes. They are termed due to the reason that they are red in colour due to the presence of the haemoglobin pigment. Moreover, the haemoglobin pigment behaves as an oxygen carrier in the blood.

Complete answer: The red blood cells are also called erythrocytes. An average man possesses about four to five million red blood cells in every millimetre cube of his blood. On the other hand, an average woman possesses five to six million red blood cells in every millimetre cube of the blood. Children possess approximately nine million red blood cells in every millimetre cube of their blood. The shape of the red blood cells is usually observed as biconcave. Moreover, red blood cells are non-nucleated, that is, they do not possess a nucleus.
a) Aerobic respiration: An aerobic respiration is defined as the respiration that occurs in the presence of oxygen as RBC does not have a nucleus, they do not carry oxygen, so they do not perform aerobic respiration.
b) DNA replication: It is the process of duplication of DNA and DNA is present inside the nucleus, so they do not have nucleus thus, they do not perform DNA replication.
RNA synthesis: RNA synthesis occurs from DNA which takes place inside the nucleus, so they lack this process as well.
Hence, the correct answer is option D.

Note: The immature red blood cells show the presence of a nucleus. But, it is removed from the mature red blood cells. It is done in order to accumulate more and more haemoglobin in the red blood cells. The presence of a nucleus would require some space and volume, so to use the maximum volume, the mature red blood cells destruct their nucleus.