What kind of cells do mitosis produce

But how does this process proceed, and what sorts of cells does it produce? During mitosis, a eukaryotic cell undergoes a carefully coordinated nuclear division that results in the formation of two genetically identical daughter cells.

Mitosis itself consists of five active steps, or phases: prophase, prometaphase, metaphase, anaphase, and telophase. Before a cell can enter the active phases of mitosis, however, it must go through a period known as interphase , during which it grows and produces the various proteins necessary for division.

Then, at a critical point during interphase called the S phase , the cell duplicates its chromosomes and ensures its systems are ready for cell division.

If all conditions are ideal, the cell is now ready to move into the first phase of mitosis. This page appears in the following eBook. Aa Aa Aa. Walther Flemming's drawing of chromosomes. What happens during mitosis? Figure 1: During prophase, the chromosomes in a cell's nucleus condense to the point that they can be viewed using a light microscope.

Prophase is the first phase of mitosis. During this phase, the chromosomes inside the cell's nucleus condense and form tight structures. In fact, the chromosomes become so dense that they appear as curvy, dark lines when viewed under a microscope Figure 1.

Because each chromosome was duplicated during S phase, it now consists of two identical copies called sister chromatids that are attached at a common center point called the centromere.

Figure 2: The mitotic spindle white begins to form outside the cell's nucleus. Important changes also take place outside of the nucleus during prophase. In particular, two structures called centrosomes move to opposite sides of the cell during this phase and begin building the mitotic spindle.

The mitotic spindle plays a critical role during the later phases of mitosis as it orchestrates the movement of sister chromatids to opposite poles of the cell Figure 2. After prophase is complete, the cell enters prometaphase. Like prokaryotes, single-celled eukaryotes, such as amoeba and yeast, also use cell division as a method of asexual reproduction.

For complex multicellular eukaryotes like plants and animals, cell division is necessary for growth and the repair of damaged tissues.

Eukaryotic cells can also undergo a specialized form of cell division called meiosis , which is necessary to produce reproductive cells like sperm cells, egg cells and spores. The eukaryotic cell cycle is a series of well-defined and carefully timed events that allow a cell to grow and divide.

G1 phase first gap phase : During this phase cells that are intended for mitosis, grow and carry out various metabolic activities. S phase synthesis phase : During this phase, the cell duplicates its DNA. Eukaryotic DNA is coiled around spherical histone proteins to create a rod-shaped structure called the chromosome. During the S phase, each chromosome generates its copy, or sister chromatid.

The two sister chromatids fuse together at a point called the centromere, and the complex resembles the shape of the letter "X. G2 phase second gap phase : During this phase the cell continues to grow and generate proteins necessary for mitosis.

M phase mitosis : Mitosis involves the segregation of the sister chromatids. A structure of protein filaments called the mitotic spindle hooks on to the centromere and begins to contract. This pulls the sister chromatids apart, slowly moving them to opposite poles of the cell.

By the end of mitosis each pole of the cell has a complete set of chromosomes. The nuclear membrane reforms, and the cell divides in half, creating two identical daughter cells.

Chromosomes, become highly compacted during mitosis, and can be clearly seen as dense structures under the microscope. The resulting daughter cells can re-enter G1 phase only if they are destined to divide. Not all cells need to divide continuously. For example, human nerve cells stop dividing in adults. A group of cancerous cells produces a growth called a tumour.

Chemicals and other agents that can cause cancer are called carcinogens. Carcinogens cause cancer by damaging DNA which can cause mutations to occur. A single mutation will not cause cancer — several are required. For this reason, we are more likely to develop cancer as we get older. There are certain genetic factors that increase the likelihood of developing some cancers. Something that increases the likelihood of developing a disease is called a risk factor.

During prometaphase, the nuclear envelope that encloses the nucleus breaks down, and the nucleus is no longer separated from the cytoplasm. Protein formations called kinetochores form around the centromere. The mitotic spindle extends from the poles and attaches to the kinetochores. During metaphase, the microtubules pull the sister chromatids back and forth until they align in a plane, called the equatorial plane, along the center of the cell.

During anaphase, the sister chromatids are separated simultaneously at their centromeres. The separated chromosomes are then pulled by the spindle to opposite poles of the cell.