A red blood cell contains a large nucleus; it is thicker near the center and thin around the rim of the cell:
A.
False
B.
True.
The correct answer and Explanation is :
The correct answer is: A. False
Explanation:
Red blood cells (RBCs), also known as erythrocytes, are unique among the cells in the human body due to their highly specialized structure and function. One of their most important characteristics is that they do not contain a nucleus once they mature. This lack of a nucleus maximizes the space available inside the cell for hemoglobin, the protein responsible for carrying oxygen.
RBC Structure:
Red blood cells have a distinct biconcave shape. This means that they are thinner in the center and thicker around the edges or rim, resembling a shallow bowl. This shape is highly functional, as it increases the cell’s surface area relative to its volume, optimizing the exchange of oxygen and carbon dioxide. It also allows the RBCs to be flexible, enabling them to squeeze through tiny capillaries.
Why No Nucleus?
In humans and most mammals, immature red blood cells (called erythroblasts) contain a nucleus during their early stages of development. However, as they mature, the nucleus is ejected to make more room for hemoglobin. The absence of a nucleus enables the red blood cell to carry more oxygen and navigate through the bloodstream more efficiently. However, this also means that mature RBCs cannot divide or repair themselves, and they have a limited lifespan of about 120 days.
Summary of the Key Points:
- Mature red blood cells do not contain a nucleus.
- Their biconcave shape helps in oxygen exchange and increases flexibility.
- The absence of a nucleus allows more room for hemoglobin but limits the cell’s ability to repair itself.