Mitosis is the vegetative cell division in eukaryotes that regenerate the cells in tissues and organs. The body of a multicellular organism is made up of a large number of tiny cells. From conception to adulthood, the number of cells increases drastically, and these bulk of cells are differentiated into somatic cells during cell specialization. Specific types of cells specialized to perform a specific function are organized into tissues or organs. A mechanism should be there to produce a bulk of cells during embryonic development and to regenerate the cells in tissues and organs during adulthood. Mitosis, a cell division mechanism, is involved in this production of new cells from the existing cells. The most significant feature of mitosis is that it maintains the amount of genetic material of parent cells over generations.
Key Areas Covered
1. What is Mitosis
– Definition, Stages, Result
2. How Does Mitosis Result in Tissues and Organs
– Role of Mitosis in Tissue Regeneration
Key Terms: Cell Division, Embryonic Development, Mitosis, Somatic Cells, Tissue Regeneration
What is Mitosis
Mitosis is the vegetative cell division in eukaryotes where a parent cell divides into two daughter cells. The two daughter cells are genetically identical, and they contain equal amounts of genetic material, organelles, and cytoplasm when compared to their parent cell. The two phases of the cell cycle are the mitotic phase and the growth phase. The mitotic phase is called the M phase of the cell cycle. Before entering the M phase, the genetic material, as well as organelles, are replicated during the S phase of the growth phase. Prophase, metaphase, anaphase, and telophase are the stages of the mitosis. The stages of mitosis are shown in figure 1.
Figure 1: Stages of Mitosis
Mitosis is the nuclear division of the parent cell with a doubled amount of genetic material. The following cytoplasmic division is known as cytokinesis. At the end of cytokinesis, the parent cell results in two daughter cells.
How Does Mitosis Result in Tissues and Organs
The zygote is the conceptus of fertilization, and it consists of a single cell. In animals, it is often diploid. In order to form a multicellular organism, the zygote should be divided into many cells. This occurs through the rapid division of the zygote by mitosis. Mitosis results in a bulk of cells that are further specialized into various types of cells, performing certain functions of the organism. Specialized cells for a particular target are collectively known as a tissue, and several tissues are involved in the formation of an organ. An organ also performs a particular function within the body. Mitotic stages of apical meristem are shown in figure 2.
Figure 2: Mitosis in Apical Meristem
However, the cells within a tissue or an organ should be regenerated either in normal cell turnover or by filling the lost cells by an injury. Mitosis plays a vital role in regenerating the cells of a tissue by producing new cells from existing cells. Since tissues and organs consist of specialized cells, mitosis should be able to produce daughter cells specialized for the same function. Most of the specialized somatic cells undergo mitosis. However, some specialized cells such as nerve cells do not undergo mitosis. These cells remain in the body through the lifetime. Adult stem cells also divide by mitosis to renew cell populations.
Conclusion
Mitosis is the vegetative cell division in eukaryotes. The cells in tissues and organs are maintained and regenerated by the production of new cells by mitosis. Mitosis produces two identical daughter cells to the parent cell. During the embryonic development, mitosis is involved in the production of bulk of cells from a single cell known as zygote. The somatic cells of the body of multicellular eukaryotes are originated into tissues that are specialized to perform a particular function within the body.
Reference:
1. “How Cells and Tissues Grow.” Cancer Research UK, 24 Nov. 2017, Available here.
Image Courtesy:
1. “0331 Stages of Mitosis and Cytokinesis” By OpenStax – (CC BY 4.0) via Commons Wikimedia
2. “Mitotic Stages in Apical Meristem of Allium Root Tip” by Berkshire Community College Bioscience Image Library (Public Domain) via Flickr
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