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What is Mitosis?

In 1887, the German anatomy biologist, Water Fleming, coined the ax mitosis which comes from the Greek language and translates to “wrap thread” indigenous mitos and “act or process” native the osis part of mitosis. This ax was based upon the warped thread appearance of the chromatin of the cell nucleus in the first stages the mitosis. Now, what is mitosis together a process? Mitosis is the procedure in cell division by i beg your pardon the cell core of the cell divides (in a lot of phase), providing rise to two the same daughter cells.

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Mitosis happens in all eukaryotic cells (plants, animals, and also fungi). It is the procedure of cabinet renewal and growth in a plant, pet or fungus. The is continuously arising throughout our bodies; that is also happening while friend are analysis this. Cells repeatedly die; this procedure is termed apoptosis (programmed cabinet death). For you to stay alive and totally functional, these cells should be repeatedly replaced. Mitosis is an essential to this process. Mitosis is the factor we have the right to grow, heal wounds, and also replace damaged cells.

Mitosis is likewise important in organisms which blee asexually: this is the only means that these cells deserve to reproduce. This is the one an essential process that sustains populaces of asexual organisms. Mitosis allows for part organisms to main alternating life step (asexual and also sexual, such together fungi).

The key to mitosis developing is the visibility of a nucleus. Therefore, organisms without nuclei (prokaryotes) miss out on out on this superior process.

Before Mitosis

Before mitosis begins, the chromosomes in the cell nucleus of the cabinet undergo replication. This is since mitosis produces 2 daughter cells the same to the parent cell; therefore the variety of chromosomes in the parent and also daughter cells should be the same. Mitosis produces two diploid cells from one diploid cell. Thus, chromosome numbers must double before mitosis occurs. Save in mind; diploid refers to the variety of chromosomes in a cell: haploid cells have actually one collection of chromosomes (n), together is found in a gamete (sex cell), conversely, diploid cells have two to adjust of chromosomes (2n).

Overview the Mitosis

During mitosis, every chromosomes separate into chromatids (the 2 halves the a chromosome). This chromatids space then be separate in room before cabinet division, to kind the chromatic assembly of every daughter cell. Due to the fact that there are double the number of diploid chromosomes in the parental cell (2 X 2n = 4n), once these chromosomes room separated right into their chromatids and split right into two groups, each team will have actually the same number of chromatids, and therefore chromosomes, together each other and also as the parent cell. The composition of this chromosomes will likewise be identical. Once the chromosomes room separated in space, cell division occurs to create two daughter cells. Thus, mitosis offers chromosome replication to produce two similar diploid daughter cells, which space genetically similar to the diploid parent cell. This way all your cells have actually identical DNA composition.

The Phases that Mitosis

The process of mitosis can be mental boggling to understand fully; below we will shot to work through the systematically. An initial off, mitosis can be separation into 5 phases: Prophase, prometaphase, metaphase, anaphase and also telophase. Some textbooks vary in the variety of phases. In part instances they perform away through prometaphase and just keep the four fundamental phases.

What precisely happens in every phase of mitosis in pets may differ to what happens in plants. Nonetheless, every cells undergoing mitosis will in one way or one more undergo each of the over mentioned phases.

You will have to familiarize yourself with the following terms to completely understand the phases that mitosis explained below:

Cell furrow/cleavage furrow
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Image Source: Flickr
The indentation uncovered in the cell membrane the a recently divided pet cell
Cell plateThe synthesized department of a plant cell laid throughout the metaphase plate. This later forms the center lamella
CentrioleImage Source: Wikimedia CommonsAn organelle linked with spindle fiber production, situated in the centrosome. These space only uncovered in animal cells
CentrosomeThe part of the cytoplasm which contains the centrioles
Microtubules

 

Hollow protein pipe which form spindle yarn (among various other things)
Tubulin
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Image Source: Wikimedia Commons
The protein which provides up microtubules
Kinetochore microtubules 

Image Source: Wikimedia Commons
The microtubules which affix the centrosome to the kinetochore
KinetochorePlates the protein in ~ a chromosome’s centromere, come which spindle fibers affix during mitosis
Centromere
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Image Source: Wikimedia Commons
The suggest of constriction that a chromosome
Cohesin 
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Image Source: Wikimedia Commons
The protein which binds 2 sister chromatids
Cytokinesis
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Image Source: Wikimedia Commons
Division the the cytoplasm into two equal parts
Equatorial plane/metaphase plate
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Image Source: Wikibooks.org
The midline of the cell follow me which chromosomes align throughout metaphase
Interphase
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Image Source: Wikimedia Commons
The duration between mitosis occurrences; the period between one telophase and the next prophase
Middle lamella
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Image Source: Wikimedia Commons
The cell structure between surrounding plant cell walls
Nuclear envelope 
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Image Source: Wikimedia Commons
The dual membrane which encloses the nucleus
NucleolusThe center of rRNA production within the nucleus
Sister chromatids
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Image Source: Wikimedia Commons
The two the same chromatids which form a chromosome
Spindle fibersImage Source: Wikimedia CommonsA bundle of microtubules running from one pole of the cabinet to another, follow me which chromosomes move

Now that the meanings are the end of the method let us obtain started on the nitty gritty the this process.

1. Prophase

This is the longest step of mitosis. Plenty of important occasions occur in this phase, the centrioles migrate, the spindle fibers space organized, the nuclear envelope disintegrates, the nucleolus likewise disintegrates, and also the dyed fibers condense (Figure 1).

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Figure 1: The major events occurring in the prophase stage picture Source: Wikimedia Commons

Prophase in pet cells begins with the hike of 2 pairs of centrioles indigenous just external the nucleus, in the centrosome, come polar end of the cell. When at polar ends of the cell, the centrioles promote the movement of microtubules from the cytoplasm into the spindle fibers. Plant and also fungi cells execute not have centrioles; therefore, castle skip this step.

While this is occurring, the nuclear envelope and nucleolus disintegrate, publication the dyed within. The dyed condenses, and also chromosomes become visible. The 2 chromatids making up each chromosome are identical and are known as sister chromatids. These are hosted together by cohesin.

Think that this phase this way, every part of the cell the is affiliated in mitosis alters to prepare because that the full mitotic process. For example, in ~ the end of mitosis the daughter cells need equal amounts of similar DNA, so there has to be a means of making sure that the right contents go to the ideal cell. In various other words, there needs to be an insurance device for making certain that one cell does not finish up through two copies of the one chromosome when the various other cell ends up through zero duplicates of this chromosome. This is achieved through the hard work that spindle yarn which pull the components of the one daughter cabinet to the one side while the various other “half” is pulled in the direction of the the opposite end. This way, chromosomes never acquire lost and go come the dorn end. In short, things move to your rightful corners.

The existence of the atom envelope borders how far chromosomes, in particular, deserve to go. So prior to the cabinet can consider pulling things apart and also duplicating the contents, this obstacle need to be removed somehow. This is why the nuclear envelope disintegrates.

If you monitor the logic above it should be apparent why the other occasions occur. Review over the explanation presented below of the entire procedure and then go.

2. Prometaphase

Prometaphase is one intermediary stage in between prophase and also metaphase, below the cell is further prepared for metaphase (figure 2).

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Figure 2: The events of the prometaphase stage. Image Source: Wikimedia Commons

The spindle fibers affix to the kinetochore of every chromosome, in ~ opposite sides of the centromere. Each sister chromatid is attached come its spindle fibers. These spindle fibers are comprised of kinetochore microtubules. The chromosomes migrate to the equatorial aircraft (or metaphase plate), i beg your pardon is perpendicular to the spindle fibers.

Here the exact same logic as over applies; that is all around making sure one chromatid end up in one cell.

3. Metaphase

Metaphase describes the alignment the the chromosomes in ~ the equatorial plate adhering to prometaphase.

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Figure 3: The alignment the chromosomes in ~ metaphase. Picture Source: Wikimedia Commons

Each centromere is aligned v the equatorial plate while the chromosome arms prolong towards the poles. Each sister chromatid (still join at this point) is on a different side of the equatorial bowl (figure 3).

4. Anaphase

The Anaphase phase is the shortest phase of mitosis.

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Figure 4: sisters chromatids are pulled in the direction of opposite poles that the parent cell. Image Source: Wikimedia Commons

During this phase, disjunction occurs, and also migration that sister chromatids away from each various other to the poles that the cabinet occurs, resulting in the formation of daughter chromosomes.

Molecular motors use ATP come shorten the spindle fibers attached to each sister chromatid. In for this reason doing, the chromosomes are split into 2 genetically similar sister chromatids, well-known as daughter chromosomes native this point. This occasion is well-known as disjunction. As the spindle yarn shorten further, the daughter chromosomes are drawn further apart till grouped at opposite end of the cell.

There is now a diploid variety of chromosomes at every pole.

5. Telophase

Telophase is the final phase of mitosis. After ~ anaphase, 2 diploid sets of chromosomes are located at each pole the the cell. Cytokinesis then occurs to split the cell right into two the same daughter cells.

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Figure 5: The parental cabinet constricts to type two daughter cells similar to each other and also the parental cell. Photo Source: Wikimedia Commons

In pet cells, the cytoplasm is constricted come the suggest that the cell is divided in two. This results in a cabinet furrow. In tree cells, a cell plate is laid in ~ the position of the equatorial plane. This later becomes the middle lamella the the plant cell.

Following this, chromosomes room packed to become chromatin, a nucleolus reforms, and also a nuclear envelope forms around the chromatin and also nucleolus. The spindle yarn disappear, and the cabinet enters interphase.

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Figure 6: A simplified outline of mitosis. Picture Source: Wikimedia Commons

Now that we have explored all the various stages go back reread and shot to factor each event. This will administer you v the capacity to answer any kind of questions about each and every one of these stages.

Why is Mitosis Important?

Mitosis is crucial for three main reasons: development and expansion cell replacement and also asexual reproduction.

1. Advance and growth

After meiosis has developed a gamete, and this has fused with another gamete to form an embryo, the embryo grows using mitosis. This growth continues throughout an organism’s life, in plants, animals, and also fungi. In this way, the original chromosomal set is preserved.

2. Cell replacement

This occurs as soon as the initial cell is damaged or wounded. Brand-new cells are created to change those the were damaged. Instances of this room the heal of a cut or a broken bone. When old cell die, brand-new ones replace them to ensure continuing functionality.

3. Asexual reproduction

Single-celled organisms and certain multicellular organisms usage mitosis for asexual reproduction. This contains reproduction by fragmentation, as in the instance of planaria, and also reproduction by budding, together in the situation of sea anemones. Plenty of plants reproduce making use of mitosis.

How is Mitosis various from Meiosis?

First, we need to recognize what meiosis is. Meiosis is the replication of cells that outcomes in each daughter cell nucleus containing half of the parent cell’s chromosomes. Meiosis is used generally for the manufacturing of gametes, i beg your pardon are included in sexual reproduction. Thus, the key difference in between mitosis and meiosis is the mitosis produce somatic (body) cells, which deserve to go on to become component of any bodily tissue, conversely, meiosis only produces germ (sex) cells. Biology which reproduce asexually cannot undergo meiosis, whereas all eukaryotic bio organisms undergo mitosis.

Mitosis and meiosis are similar in that both deserve to only happen in eukaryotic bio cells. This is due to the fact that prokaryotic cells do not save a nucleus in ~ which to start the processes of mitosis and meiosis. Instead, prokaryotes replicate themselves using binary fission. Both mitosis and meiosis begin with DNA replication in the parental cell to produce four set of chromosomes: in mitosis, these sets are separation to type two diploid daughter cells, while in meiosis, these sets are separation to form four haploid daughter cells. This is because cells undergo just one division in mitosis, conversely, they undergo two divisions in meiosis.

The table listed below summarizes the similarities and also differences in between mitosis and meiosis.

Mitosis

Meiosis

Similarities

Can only happen in eukaryotes
DNA replication wake up first
Production the daughter cells based upon parent cell’s hereditary material
Means of cell replication in plants, animals, and fungi

Differences

Starts together diploid; ends as diploidStarts together diploid; ends together haploid
Used for growth/healing/asexual reproductionUsed for sexual reproduction
1 atom division2 atom divisions
5 phases8 phases
Daughter cell identical to parent cellDaughter cabinet not similar to parent cell
Results in 2 daughter cellsResults in 4 daughter cells
Produces somatic cellsProduces germ cells
Occurs in asexual and also sexual organismsOccurs just in sex-related organisms

Wrapping up Biology and also Mitosis

We now understand that mitosis is the process of asexual cell replication that is responsible because that an organism’s development and growth, its cabinet replacement, and also, in particular organisms, asexual reproduction. Mitosis is, therefore, one integral part of eukaryotic functioning. Mitosis different from meiosis in the meiosis is the manufacturing of gametes, or sex cells, i m sorry will enable for genetic recombination in sexual organisms. However, without mitosis, the embryos formed will never prosper to come to be organisms. Mitosis is preceded by DNA replication, to type two diploid sets of chromosomes. Mitosis has 5 phases. The first stage is prophase, where the chromatic material is exit from the nucleus, and centromeres migrate to the poles the the cell. Prophase is adhered to by prometaphase, wherein the chromosomes move to align in ~ the equatorial aircraft of the cell. The 3rd phase is metaphase, whereby the chromosomes are fully aligned in ~ the equatorial plane. Metaphase is complied with by anaphase, inside the sister chromatids forming each chromosome space pulled apart to assemble at the poles that the cell; and also telophase, wherein cytokinesis forms two similar daughter cells, genetically the same to the parent cell. Complying with this, the cell enters interphase, the phase in between mitosis events.

Mitosis has given eukaryotic organisms the capability to regenerate cells as important without reduce the chromosome set while meiosis has permitted the possibility of hereditary recombination. Both are vital for the prevalence and also continued survive of eukaryotic bio organisms.

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