Mitosis : Phases of Mitosis, Examples, | FAQs

Mitosis : Phases of Mitosis, Examples, | FAQs


This time we will discuss about mitosis? May be you have heard the word mitosis? Here the we discusses in detail about the definition, characteristics, objectives, functions, processes, examples. See the following explanation carefully, don't miss it.

Introduction to Mitosis : 

Mitosis, which comes from the Greek term for "tissue," is a segmentation of cells that occurs after genetic material is duplicated, allowing each cell produced to have all of the chromosomes.

Therefore, the act of distributing hereditary information found in DNA is fair. The mitosis process produces genetically identical cells. Meiosis (another process of cell division), by contrast, produces cells that are genetically different.

In summary, mitosis is a procedure in which cells multiply and have a great impact on the growth, development and regeneration capacity of the organism. The conformation of the two new nuclei is known as karyokinesis, while the cytoplasmic division is called cytokinesis.

When it comes to mitosis, it is important, we know that this process is divided into four distinct stages or phases, the first of which is called prophase. In this case, the chromosomes can already be seen under a microscope and they stand out because they are made up of bars, called chromatids, that join together.

The second stage is what is called metaphase and what happens is that the pair of chromatids moves towards what is the center of the cell. Next, a third step called anaphase occurs, which we can determine as the most important stage of mitosis because division, transport, and distribution of the two copies of the original genetic information are performed.

Finally, the fourth and last phase is what is called telophase. In this case, it is a time when the process of the previous stage is reversed, resulting in the acquisition of two daughter cells that are characterized by the division of the cytoplasm and the same chromosome. It is also important to note that when mitosis occurs in multicellular organisms, it not only results in new individuals, but also in the recovery of dead cells, the regeneration of damaged tissues, and wound healing.

Read : Cell Structure & Functions

Mitosis can also occur in different ways, not including cell division. Called endomitosis or endoreduplication, this process produces cells with copies of the chromosomes in question in the same nucleus. The cells produced by endomitosis are called endoploids. It should be noted that errors can occur in mitosis, although it rarely occurs. They generally occur in the earliest cell segmentation in zygotes and affect the decline of damaged stem cells.

A chromosome that does not separate at a stage known as anaphase and damage to the chromosomes caused by changes in the cellular structure that produce processes is another problem that can arise during mitosis. There are times when errors can be detected and corrected in time. Mitosis is a process in which an individual cell divides into two identical daughter cells (cell division).

Definition of mitosis

This is a type of cell division
in which a cell divides to form two similar
daughter cells which are identical to the parent cell.

Mitosis is cell division that occurs in eukaryotic organisms. Mitotic cell division takes place in somatic tissue. In this mitotic division, one cell divides into two identical cells. cell division that takes place on a network of growth points (meristems), such as at the tips of the roots or shoots of plants. The mitosis process takes place in four phases, namely prophase, metaphase, anaphase and telophase. The mitosis phase takes place in plant cell and animal cells. There are fundamental differences between mitosis in animals and plants. Mitotic division occurs at the time of embryonic development and growth, replacing aged cells such as blood cells, skin, intestinal wall, etc., and wound healing.


What is Mitosis?

Cell division is a process of reproduction at the cellular level. Most eukaryotic cells divide in a way where the ploidy or the number of chromosomes remains the same, except in the case of germ cells where the number of chromosomes is halved.

Mitosis is the phase of the cell cycle in which the cell nucleus is divided into two nuclei with the same amount of genetic material in the two nuclei of the child. This succeeded in the G2 phase and was replaced by cytoplasmic division after the separation of the nucleus.

Mitosis is very important for cell growth and replacement of worn cells. Abnormalities during mitosis can change DNA, resulting in genetic disorders.

Characteristics of mitosis

Below are the characteristics of mitosis, among others, as follows:
  1. During the process of mitosis, division takes place once. 
  2. Takes place on somatic cells.
  3. It generally produces two saplings identical to its mother.
  4. The number of chromosomes in a child is the same as the number of chromosomes in a parent, namely 2n (diploid).
  5. One division will take place, including: Profase - Metaphase - Anaphase - Telophase
  6. The nature of daughter cells is the same as stem cells.
  7. Occurs in body cells (somatic cells), for example in embryonic tissue, including root tips, stem tips, cambium circles.
  8. Between division one with the next division interspersed with interphase (rest does not share)
  9. The daughter cell has the same number of chromosomes as the parent, of the same nature as the parent
  10. The daughter cell can divide again
  11. Can occur in young organisms, adults or old age.


The purpose of Mitosis

  1. The purpose of mitotic division is to multiply the cells used for the growth process, as well as to produce two sapling cells, each of which has daughter cells that have the same characteristics and number of chromosomes as the parent.
  2. Mitosis is responsible for the development of zygotes into adults.
  3. Chromosomes are distributed evenly to daughter cells after each cycle.
  4. Mitosis is responsible for the exact shape, and proper growth and development of an individual.
  5. It maintains a constant number of chromosomes in all body cells of an organism.
  6. In plants, mitosis helps in the formation of new parts and repair damaged parts. Mitosis also helps in vegetative propagation of plants.
  7. Because no recombination and separation occur in the process, it helps in maintaining the purity of the species.
  8. Mitosis helps in maintaining a balance between DNA and RNA content as well as nuclear and cytoplasmic cell content.
  9. It is responsible for replacing dead and old cells in animals: For example, intestinal epithelium, and blood cells.

Read : DNA Replication


Functions of Mitosis 

Mitosis serves as a basic mechanism capable of repairing eukaryote tissue for all multicellular species. Mitosis also forms the basis of asexual reproduction in single cells and several eukaryotes and multicellular cells. And the replacement of cells that have been damaged or have died.

Process of Mitosis

This is a type of cell division
in which a cell divides to form two similar
daughter cells which are identical to the parent cell. It is completed in two steps as karyokinesis and cytokinesis.

Karyokinesis is nuclear division which
is sub-divided into prophase, metaphase,
anaphase, and telephase. Although for the
sake of convenience above mentioned steps are used, it must be remembered that mitosis is a continuous process that starts with the disappearance of nuclear membrane in prophase and ends with separation of two fully formed cells after cytokinesis.

Mitosis : Phases, Functions


Here are some of the processes or stages of mitotic division, including the following:

A. Karyokinesis 

1. Prophase

At this stage the chromatin fibers will gather more tightly together, the cell nucleus will disappear, each duplicated chromosome is seen as the same two chromatids connected by the centromere and along the arm. Mitotic spindles also begin to form, consisting of centrosomes and microtubules which extend from the centrosomes. The centrosomes move away from each other, driven by microtubules which extend between them. In this phase, fragments are formed, small fragments that occur due to damage to the cell nucleus membrane. Until this stage the cleavage process has begun to form and the chromatin yarns have begun to solidify which then produces chromosomes. At the end of this stage the chromosomes will start moving to the center of the cell.

Prophase
Fig: Prophase

2. Metaphase

Metaphase is the longest stage of mitotic division, lasting about 20 minutes. In this phase, the chromosome will move toward the equator of the cell or often known as the metaphase plate. At this stage, the membrane will completely disappear and the spindle will reach the centromere chromosomes. In the kinetochore metaphase each chromosome divides, and the two chromatids become completely separate child chromosomes. Under the control of a mechanism hitherto unknown, cleavage of the kinetochore occurs simultaneously on all chromosomes. The child kinetochore starts to move apart, which marks the start of the phase.

Metaphase
Fig: Metaphase

3. Anaphase

In contrast to metaphase, this phase of anaphase is the shortest stage of mitosis, lasting only a few minutes. At this stage of anaphase, the sibling chromatids will separate from the centromere so that they are called chromosomes. Each chromosome will be pulled towards the pole by the threads of mitosis or often called kinetochore fibers. At this stage the cell will elongate when the nonkinocochorous microtubules extend, and at the end of the anaphase, both ends of the cell will have the same and complete collection of chromosomes.

Anaphase
Fig : Anaphase 


4. Telophase

At this stage, two nucleus saplings will form in the cell, the chromosomes will begin to detach. Telophase itself is often marked by the start of cytokinesis. In animal cells, cytokinesis begins with the formation of division or indentation in the middle which divides the cell into two. Whereas in plant cells, cytokinesis is characterized by a series of vesicles that form at the equator of the cell, which continue to occur until the cell divides in half. At the end of the telophase stage two puppies are produced which are the same as the parent cells.

Telophase
Fig : Telophase


5. Prometafase

Prometaphase is sometimes seen as the end of prophase and initial metaphase. During the initial stages of prometaphase the nuclear membrane is destroyed and microtubules enter the nuclear space. This is known as "open mitosis" and it occurs in most multicellular organisms. Organisms such as fungi, some protists such as algae undergo "closed mitosis" in which the formation of spindles that occur in the nucleus. Nuclear membranes remain intact and microtubules are unable to penetrate intact nuclear membranes. During prometaphase, the centromere of each chromosome forms two kinetochores. Kinetochore is a complex protein structure, it is a type where microtubules attach to a chromosome.

B. Cytokinesis

The division of cytoplasm
In two daughter cells is called cytokinesis.
The division begins with a concussion. this
The tension gradually deepens and ultimately The center is divided between two daughters Cells. This process of division of cytoplasm is Perpendicular to the axis. This system Cytokinesis is a characteristic of animal cells. However, plant cells are covered by A. Relatively non-flexible cell wall. Because of this, Fur cannot be formed. Instead, the cell wall / Division appears in the center of Moves out to meet cell and current Lateral walls. Formation of new cell
The wall begins with the formation of a simple The precursor represents the 'cell-plate' Middle lamella between two walls
Adjacent cells. At the time of cytoplasmic division, Organisms like mitochondria and plastids are found Distributed between two daughter cells.

Read : Somatic Cell

Examples of Mitosis 

In mitosis cell division results in 2 genetically similar saplings. That is, the two sapling cells formed have the same genetic makeup as the parent. Almost all living things undergo the same process of mitosis, except in prokaryotes (living things that do not have a true core) such as bacteria, viruses and blue algae. The mitotic cycle of a cell can be divided into two stages, namely interphase (resting stage) and mitosis (staging division). Interphase is the period between one division and the next in the cell division cycle.


Advantages of Mitosis

Mitosis creates an identical copy of the original cell. This allows our skin or liver to be made from identical cells and allows plants to be able to mass-produce leaves with identical properties. Imagine if each of our skin cells had a different DNA!

Disadvantages of Mitosis

Some single cell organisms and some plants do not reproduce sexually through meiosis. Instead, they use mitosis only to make exact copies of their cells. The main disadvantage of this approach is that all organisms in a population or all plants in an area will have the exact same DNA. If a new disease arises, every organism or plant will be destroyed because if one organism or plant is unable to fight the disease it means that no one can fight the disease.

Mitosis also does not produce any variation. So, plants that reproduce through mitosis will not have the opportunity to produce offspring that may be better than the parent.

Significance of mitosis : 

  1. As mitosis is equational division, the chromosome number is maintained constant. It ensures equal distribution of the nuclear and the cytoplasmic content between the daughter cells, both quantitatively and qualitatively. 
  2. The hereditary material (DNA) is also equally distributed. 
  3. It helps in the growth and development of organisms. Old and worn-out cells are replaced through mitosis. 
  4. It helps in the asexual reproduction of organisms and vegetative propagation in plants. 
  5. The process of mitosis also maintains the nucleo-cytoplasmic ratio. 
  6. Although mitosis is a very reliable process  for preserving the genetic make-up of cells or organisms, it cannot introduce variation or new combination of existing genes.


Frequently Asked Questions on Mitosis

What is mitosis and its stages?
Answer : These stages are early, mid, mid, late, and end. During mitosis, the copied chromosomes coagulate and attach to the spindle-shaped fibers, which pull a copy of each chromosome to the opposite side of the cell.


What are examples of mitosis?
Answer : The cell undergoing mitosis will be any somatic cell such as skin cells. You can also ask about any practical applications of mitosis. Healing is an example of mitosis, growth is an example of mitosis, and even cancer is an example of mitosis.


How does mitosis occur?
Answer : Mitosis is the process of cell division. The nucleus divides through the process of division (multiphase division), resulting in two identical daughter cells. Mitosis occurs in all eukaryotic cells (plants, animals and fungi).


What happens after mitosis?
Answer : Once mitosis is complete, the entire cell is divided into two parts through a process called cytokinesis. Flemming has repeatedly observed different forms of chromosomes that cause cell division and division. This is the final stage of mitosis that divides a cell into two parts.


Where does mitosis occur in the body?
Answer: Mitosis occurs in every cell in the body, except for the germ cells produced by the division of meiotic cells.


How can mitosis help us survive?
Answer: In larger organisms, mitosis plays a different role in survival. All non-germ cells of the human body are divided by mitosis, such as skin cells, muscle cells and blood cells. Mitosis helps organisms grow, heals wounds and replaces countless cells that shed every minute.


What are the three main functions of mitosis?
Answer: The main function of mitosis is growth and repair. Once fully formed certain cells will not undergo cell division, such as nerve cells and muscle cells. Because once these cells mature, they can never grow or repair them again, so you must take care of the cells you have.


How long does it take to complete mitosis?
Answer: Generally, it takes 5 to 6 hours for the cells to complete the S phase. G2 is shorter and lasts only 3 to 4 hours in most cells. In short, it usually takes 18 to 20 hours between phases. During mitosis, cells are ready for cell division and complete cell division, which only takes about 2 hours.