Does RBC follow cell theory?

According to this version Cells contain DNA which is found specifically in the chromosome and RNA found in the cell nucleus and cytoplasm. But the mature RBC does not contain nucleus or the cell organelles that contain genetic material so it does not fit the modern theory and hence should not be considered cell.

Why do red blood cells not replicate?

Although RBCs are considered cells, they lack a nucleus, nuclear DNA, and most organelles, including the endoplasmic reticulum and mitochondria. RBCs therefore cannot divide or replicate like other labile cells of the body. They also lack the components to express genes and synthesize proteins.

Why is RBC An exception to the cell theory?

​​​​​Mitochondria and chloroplasts have their own genetic material and can reproduce independently from the cell in which they reside. These are the exception of cell theory.As red blood cells and plateletes have these properties of cell theory they are the exceptions of cell theory.

How are red blood cells different from animal cells?

By contrast, the red blood cells of mammals lack nuclei and other internal structures found in most animal cells. This simplification allows mammal red blood cells to carry more gas-transporting proteins and to squeeze through smaller blood vessels.

Why are red blood cells flexible?

Red blood cells must be flexible to squeeze through tiny capillaries to deliver oxygen.

What was the exception to the cell theory?

Virus is an exception to cell theory as it lacks cell and protoplasm, the living substance in which all life processes take place. But it can reproduce in a living host cell, by using raw materials (nucleotides) and biosynthetic machinery (ribosomes, /RNA, enzymes) of the host cell.

Why viruses are exceptions of cell theory?

They do not contain any cell organelle like mitochondria, ribosome etc. Viruses are alive only until they are inside their host cell. They are considered to behave dead when outside the host cell. Hence, Viruses are an exception to cell theory.

How red blood cells are adapted to their function?

Red blood cells have adaptations that make them suitable for this: they contain haemoglobin – a red protein that combines with oxygen. they have no nucleus so they can contain more haemoglobin. they are small and flexible so that they can fit through narrow blood vessels.

How do red blood cells break down?

Breaking down hemoglobin Old or damaged RBCs are removed from the circulation by macrophages in the spleen and liver, and the hemoglobin they contain is broken down into heme and globin. The globin protein may be recycled, or broken down further to its constituent amino acids, which may be recycled or metabolized.

Why are red blood cells considered a cell?

Cells are the smallest unit of life that can replicate independently. It then goes on to state that All cells (except red blood cells which lack a cell nucleus and most organelles to accommodate maximum space for hemoglobin) possess DNA. Then why are red blood cells still considered cells, while they can’t replicate?

What happens to red blood cells after they become old?

Red Blood Cell Production. Due to their lack of a nucleus and other organelles, adult red blood cells can not undergo mitosis to divide or generate new cell structures. When they become old or damaged, the vast majority of red blood cells are removed from circulation by the spleen, liver, and lymph nodes.

Do red blood cells have DNA?

All cells (except red blood cellswhich lack a cell nucleus and most organelles to accommodate maximum space for hemoglobin) possess DNA. Then why are red blood cells still considered cells, while they can’t replicate?

Do red blood cells have nucleus mitochondria and ribosomes?

Unlike other cells of the body, mature red blood cells do not contain a nucleus, mitochondria, or ribosomes. The absence of these cell structures leaves room for the hundreds of millions of hemoglobin molecules found in red blood cells.