Mitosis is a fundamental process of cell division that occurs in living organisms. It facilitates the creation of new cells from existing ones, playing a role in various life processes. It is involved in the growth of multicellular organisms, enabling them to increase in size and develop complex structures. Mitosis also serves to repair damaged tissues and replace old or worn-out cells, maintaining an organism’s body. In single-celled organisms, mitosis functions as a method of asexual reproduction, allowing them to multiply.
Number of Daughter Cells
In mitosis, a single parent cell divides to produce two daughter cells. These two new cells are genetically identical to the original parent cell and to each other. This genetic sameness ensures the new cells carry the exact same genetic information as the parent cell.
Each daughter cell produced through mitosis is diploid, meaning it contains two complete sets of chromosomes. This ploidy (2n) is the same as the parent cell, maintaining the chromosome number across generations of cells. For instance, in humans, a parent cell with 46 chromosomes will produce two daughter cells, each also containing 46 chromosomes.
How Mitosis Works
The process of mitosis involves a series of steps to ensure accurate genetic distribution. Before mitosis begins, during a stage called interphase, the cell prepares for division by replicating its DNA. This replication results in two identical copies of each chromosome, known as sister chromatids, which remain joined.
The mitotic process is divided into several phases: prophase, metaphase, anaphase, and telophase, followed by cytokinesis. In prophase, the replicated chromosomes condense, becoming compact and visible. The nuclear membrane begins to dissolve, and the mitotic spindle starts to form from protein fibers.
During metaphase, the condensed chromosomes align precisely along the cell’s equator, an imaginary central line. Each sister chromatid is attached to spindle fibers from opposite poles of the cell, ensuring they are correctly positioned for separation. This alignment helps ensure proper distribution. Following this, in anaphase, the sister chromatids separate, and the individual chromosomes are pulled by the spindle fibers towards opposite ends of the cell.
Finally, telophase marks the stage where a complete set of chromosomes arrives at each pole of the cell. New nuclear membranes form around these two sets of chromosomes, creating two distinct nuclei within the single cell. Concurrently or shortly after, cytokinesis occurs, which is the physical division of the cell’s cytoplasm. This process pinches the cell in two, forming two separate daughter cells.