Question

Cell organelle not found in mature erythrocytes of many mammals is
A. Mitochondria
B. Ribosomes
C. Nucleus
D. All of the above

Answer 1

The red blood cells are the major constituents of the blood. They carry hemoglobin that gives them their characteristic red color. Red blood cells need a large space for hemoglobin to transport maximum oxygen. Also, they do not produce any proteins or energy.

Complete answer:
Red blood cells are disc-shaped cells that have large amounts of hemoglobin in them. This is a pigment that provides red color to them. Also, hemoglobin has a great affinity for oxygen and thus functions to transport it from lungs to tissues. As the major function of RBCs or Red blood cells is to carry oxygen they have no space for cellular organelles.
Option A is mitochondria. It is known as the energy production unit of the cell. But RBCs do not produce any energy, they only carry oxygen from one part of the body to others where it is required so that cells can use it in energy production. So, the mitochondria are not present in RBCs.
Option B is Ribosomes. They are called the protein production houses of the cell. The RBCs are not involved in any protein production as they have no signals from DNA that assist the process of translation to synthesize proteins. Thus, RBCs do not have Ribosomes.
Option C is the Nucleus. RBCs are enucleated cells. This means that they do not have a nucleus. The nucleus consists of DNA (Deoxyribonucleic acid) that is responsible for protein formation by the process of transcription. Without the presence of a nucleus, the Red blood cells or RBCs cannot produce proteins required for various metabolic activities inside the cell. Hence, RBCs do not contain a nucleus.
Option D states that all of the above-given organelles are not found in RBCs. This is true as the RBCs do not contain any cellular organelles like mitochondria, ribosomes, nucleus, Golgi apparatus, endoplasmic reticulum, etc.
Therefore, the correct option is option D.

Note: Despite the absence of essential cellular organelles, the RBCs are the most important cells of the human body. They provide oxygen that is the most essential molecule required by other cells of the body to produce energy. Also, the RBCs have a very short life span as they do not produce their own energy.