To see with chromosomes in metaphase mitosis. mitosis

• 1) In prophase, the volume of the nucleus grows, and after the spiralization of chromatin, chromosomes are formed. Until the end of prophase, it can be seen that the skin chromosome folds into two chromatids. The nucleus, the nuclear membrane, and the chromosomes are gradually developed, and the chromosomes are formed smoothly in the cytoplasm of the cell. The cytoplasm of cellini has a small granularity, called centrioles. On the ear of prophase, the centrioles last, and the daughter centrioles go to the prototypes of the cells. From the skin center, go through thin threads at the sight of the changes, so that the glimpse is made; between the centrioles of the vine, the spindle, which folds along a series of protoplasmic threads, called the threads of the spindle. The threads of the thread are set from a block, similar in its power to the fast sticks of meat fibers. The stench of rosetting at the sight of two cones, folded up to the base, so the spindle appears vigorous at the ends, either the poles, close to the centrioles, and wide in the center, or at the evector. The threads of the spindle are stretched from the adequate to the poles; the stench is stored with the larger protoplasm of the nucleus. The spindle is a singing structure: with the help of a micro-manipulator, you can introduce a thin head into the cell and move the spindle with it. The spindle, which is seen from the cells, is able to spread, to replace the blocks, in the main one type of wine, and also a small amount of RNA. At that hour, the centrioles rose, and the spindle was formed, the chromosomes in the nucleus were speeding up, they were short and short. If earlier it could have been, and it’s not visible, but the stench is stored in two elements, now it’s clear.
• 2) Prometaphase to recover from a sharp drop of the nuclear envelope on other fragments, from fragments of the EPR. In chromosomes from the cutaneous flank of the centromere, in the prometaphase, special structures are established, called the kinetochore. The stench is attached to a special group of microtubules, called kinetochorny threads or kinetochorny microtubules. The threads go from both sides of the skin chromosome, go in the opposite strands and interconnect with the threads of the bipolar spindle. When a whole chromosome is repaired, it crumbles intensively.
• 3) Metaphase. Chromatidis are attached to the antiphritic spindles of the kinetochor. Having tied up with tied from the center of Centrosomi, the chromatidis collapse to the spindle until the spindle is silent, while the centromeres did not vibrate along the spindle equator perpendicular to the axis. It allows chromatids to collapse without pereshkodno to the upper poles. Characteristic for metaphase, the distribution of chromosomes is even more important for the segregation of chromosomes, that is, the separation of sister chromatids. Yakscho the chromosome is “buried” in its own rus to the spindle, to start to chime and the ear of anaphase. The metaphase ends with a subtype of sister chromatids.
• 4) Anaphase is trivial to chill out all the kilin. Anaphase is repaired by the rapid splitting of the skin chromosome, which is encumbered by the subtype of sister chromatids at the points of origin in the centromere.

The chain of splitting, so that the kinetochore is distributed, does not lie in any of their subtypes of mitosis, but it moves in chromosomes that are not attached to a mitotic spindle. Allowing the polar forces of the spindle, fixing the metaphase plate, to move the dermal chromatid to the outer poles of the spindle from shvidkis close to 1 micron / min. If there is no spindle thread, then the chromosomes grow on all sides, if only one additional set of daughter chromosomes is visible, one additional set of daughter chromosomes is picked up at one pole, and the other - in the lower one. From an hour to the poles of the chromosome, start to take a V-like shape, and the top is turned to the pole. The centromere grows out of the vertex, і, the force that snakes the chromosome collapses to the pole, is applied to the centromere. Chromosomes, they spent the centromere for an hour, mitose zovsim collapse

5) The telophase is repaired in order, like the daughter's chromosome, to be stored in one chromatid, reached the poles of the cell. At the first stage, the chromosomes are known to despiralize and swell such a species, which smells like a cob of roses in the interphase (even thin threads). Around them there is a nuclear envelope, and in the nucleus a nucleus is formed, in which ribosomes are synthesized. In the process of the growth of cytoplasm, all organelles are distributed between the daughter cells more and more often. At the end, the core podil is also called karyokinesis; it is possible to see the growth of blood cells, or cytokinesis.

Table 2. Phase mitose

In most cases, the entire process of loan mitosis is from 1 to 2 years. In the roslin, it was ready to go through the path of establishing the so-called clitinous plate, so that the cytoplasm was disseminated; there is a spindle in the equatorial area, and then it grows on all sides that are within reach of the bed. The material of the clitinous plate is wobbled by endoplasmic hedgehog. Then the skin of the daughter cells fixes the cytoplasmic membrane on its own platelet, and, nareshty, on both sides of the plate, the cellulite cells are installed.

The frequency of mitosis in іnі tissues і у new species Rizko Rizna. On the other hand, in chervony cystic brain people, de in the skin in a second, 10,000,000 erythrocytes are established, in the skin a second, they are guilty of 10,000,000 mitoses.

With identical genetic material.

interphase

The first step is to take the client into mitosis, it’s the period of growth called interphase. Close to 90% of the hour of the cell, under normal conditions, can be vitrized into the interphase, as it goes into three main phases:

• phase G1: Period before DNA synthesis. The phase of the client grows in mass, ready to go.
• S-phase: the period during which DNA synthesis takes place. At a large client, the stage is completed in less than an hour.
• Phase G2: klіtina prodovzhu synthesis of additional bіlkіv zbіlshuvatisya in size.

In the last part of the interphase, the cytin is still less nucleoli. The nucleus is surrounded by a nuclear envelope, and is duplicated, but not in the form of chromatin. At the two bets, the centroids, who made a replica of one bet, roztasvani behind the boundaries of the kernel.

The phase G2 infused mitosis, which is stored in decile stages and ends with cytokinesis (subclinine).

Phase mitose:

Pre-phase (in roslin cells)

The preprophase is the pre-phase phase before the hour of mitosis, which does not occur in other eukars, such as creatures, fungi. Vona front of the prophase and is characterized by two different podіy.

Zmіni that are sent to the Preprofase:

• Osvita smuga Preprofase - a small microtubular ring pid.
• Ear of germination of microtubules in the nuclear shell.

prophase

In prophase, they condense in discrete chromosomes. The nuclear shell will break off, and the spindle will set itself on the opposite poles of the cell. Prophase (in part with interphase) is the first reference to the mitotic process.

The changes that occur in professionalism:

• The chromaticity of the fiber is transformed into chromosomes, which can be transformed into two or more centromeres. Fibers are stored in microtubules and bricks, and then they are installed in.
• In the cells of the twins of the fiber, there are some structures, called Aster, to feel the skin with a couple of centers.
• Two bet centroids (formed from a replica of one bet in interphase) go one way to the opposite poles of the cell through the raised microtubules, so that they become established between them.

Prometaphase

Prometaphase is the mitosis phase of prophase and anterior metaphase in eukaryotic somatic cells. Deyaki dzherela carry out the processes in the prometaphase until the end of the prophase cob stage metaphase.

The messages that occur in the prometaphase:

• The nuclear shell is falling apart.
• Polar fibers, which are microtubules, storage spindle fibers, move from the skin pole to the adequate cell.
• Kinetochor, which are specialized areas in the centromere of chromosomes, are attached to the type of microtubules, called kinetochorny threads.
• Kinetochore threads "interconnect" with a spindle podil.
• Chromosomes fix the mіgruvati to the center of the church.

metaphase

In metaphase, the fibers of the distance grow, and chromosomes grow on the metaphase (equatorial) plate (the area, which, however, is equally visible from the two poles).

The messages that are seen in metaphase:

• The nuclear membrane will grow.
• In the kitchens of twins, two bets spread out in opposite directions to the poles of the cells.
• Polar fibers (microtubules, spindle fiber storage) extend wider from the poles to the center. Chromosomes are replaced by a vypadkovy rank, until they come (with the help of their kinetochores) to polar fibers from both sides of the centromere.
• Chromosomes are violated on the metaphase plate from a straight cut to the spindle poles.
• Chromosomes are tightened on the metaphase plate by the equal forces of polar fibers, as they press on their centromeres.

anaphase

At the anaphase, the paired chromosomes () wake up and repair collapsing to the opposite ends (poles) of the cell. Fibers of the spindle, not tied with chromatids, are twisted and podovzhuyut the cell. In the beginning of anaphase, the skin pole is avenged by the compilation of chromosomes.

Zmіny, as seen in anaphase:

• The pair in the skin of the chromosomes will fix the problem.
• Yak only guys sister chromatids are one kind of one, the skin of them is invaded by a “new” chromosome. The stench is called daughter chromosomes.
• Behind the help of the spindle, a sub-base moves to the poles on the prototype kintini.
• Daughter chromosomes migrate to the centromeres, and the kinetochoric filaments become short, below the chromosomes and near the poles.
• When ready to telophase, the two poles of the cell also extend one from one hour of anaphase. In the beginning of anaphase, the skin pole is avenged by the compilation of chromosomes.
• The process of cytokinesis (under the cytoplasm of the worm cells) is repaired, which ends with telophase.

telophase

In the telophase chromosomes, the nuclei of new daughter cells can be reached.

Zmini that occur in telophase:

• Polar fibers continue to grow.
• The kernels are repaired at the opposite poles.
• The nuclear envelope of the new nuclei is established from the surplus of the nuclear envelope of the mother's cell and the worms of the endomembrane system.
• Z'yavlyayutsya nuclear.
• The chromosome fibers of chromosomes are growing.
• The process of changing telophase and mitosis is in the main completion, and genetically changing one cell is divided into two parts.

cytokinesis

Cytokinesis - the whole of the cytoplasm of cellini. It will be better to start before the end of mitosis in anaphase and to finish without a bar in telophase. In the end of cytokinesis, there are two genetically identical daughter cells.

daughter klitini

In the end of mitosis and cytokinesis of chromosomes, the development of chromosomes is distributed in some cases between two daughter cells. Cycling cells are identical, and the skin cells have a different set of chromosomes.

Clients, which produce through mitosis, appear as clients, which are produced through. In meiosis, a chotiri of daughter cells are established. Cyclinia є, which reveals half of the number of chromosomes from the vixen clitini. to meiosis. With the growth of the cells of the cells before the hour of late, the haploid cells grow into a diploid cell.

At the moment of onset of a cellini and before death as a result of apoptosis (programmed cell death) in an uninterrupted way of life cycle of a cellin.

Here, we will use the genetic formula of klitini, de "n" - the number of chromosomes, and "c" - the number of DNA (chromatids). I guess that one DNA molecule (one chromatid) (nc), or two (n2c), can enter the skin chromosome storage.

The clinical cycle includes a chain of stages: podil (mitosis), postmytotic (presynthetic), synthetic, postsynthetic (presynthetic) period. Three remaining periods are stored in the interphase - preparation for the bed.

Proceedings for interphase periods and reports:

• Post-mitotic period G 1 - 2n2c

Ribosomes are intensively established, ATP and all types of RNA, enzymes are synthesized, mitochondria, and cell growth grow.

• Synthetic period S - 2n4c

Trivaє 6-10 years. navazhliv_sha pod_ya ts'go period - a subtype of DNA, which, until the end of the synthetic period, the skin chromosome is composed of two chromatids. Structural DNA blocks - gistoni - are actively synthesized.

• Premitotic period G 2 - 2n4c

Short, triviaє 2-6 years old. It takes a whole hour for a vitrachine to prepare before the next process - a cellin, a cell and ATP are synthesized, a center is underwent.

Mitosis (Greek Μίτος - thread)

Mitosis is an indirect way of extending the cells, the best way to expand the middle of eukarotic organisms. For a trivial loan, it is close to 1 year. Before mitosis of cellin is prepared in the period of interphase by the synthesis of proteins, ATP and the base of the DNA molecule in the synthetic period.

Mitosis is stored in 4 phases, as far as possible in detail: prophase, metaphase, anaphase, telophase. I guess that the cellina enters mitosis with a subset of DNA (in the synthetic period). Mitosis on the butt of a cell with a set of chromosomes and DNA 2n4c is mitigated.

Having settled in the telophase of the daughter of a daughter 2n2c, they enter the post-mitotic period. Then, in the synthetic period, the subunit of DNA appears, for which the skin chromosome folds into two chromatids - 2n4c. Klitka with a set of 2n4c and drunk in prophase mitosis. This is how the cell cycle stalls.

biologically meaningful mitosis even more often:

• As a result of mitosis, daughter cells are established - genetic copies (clones) of the mother's.
• mitosis є uniformed way stateless reproduction, regeneration and protection, however, is the same for all eukars (nuclear organisms).
• Universality of mitosis to serve as Chergov's proof of the unity of all organic light.

Try to independently guess the phase of the mitosis and describe the ideas that appear in them. I give special respect to come with a camp of chromosomes, to support them with DNA molecules (chromatids).

Meiosis (from the Greek Μείωσι - change), or the reduction of the cellini is a way of making the cell, in case of any decaying material in them (the number of chromosomes), changes are made. Meiosis occurs during the establishment of statin cells (gametes) in animals and spores in roslin.

As a result of meiosis from diploid cells (2n), haploid (n) are found. Meiosis is stored in two last days, where there is a practical pause every day. Underlying DNA before meiosis is carried out in a synthetic period of interphase (as during mitosis).

As it has already been said, meiosis is composed of two subtypes: meiosis I (reduction) and meiosis II (equal). First, the number of chromosomes is called reductive (Latin Reductio - change), so that the number of chromosomes changes until the end. Another podil - equational (Latin Aequatio - zrivnyuvannya) is even similar to mitosis.

Proceed to vivchennya first podilu meiosis. As a basis, there is a cell with two chromosomes and underlings (in the synthetic period of interphase) a bit of DNA - 2n4c.

Meiosis II velmi nagaduє mitosis in all phases, as it seems, they got stuck: joke in those about mitosis. The main reason for meiosis II is meiosis I in that, in anaphase to meiosis II, it is not the chromosomes that diverge to the poles of the cell, but the chromatid (daughter of the chromosome).

As a result of meiosis I and meiosis II, they were removed from the diploid cell 2n4c haploid cellins - nc. In general and polyagaє, the essence of meiosis is the establishment of haploid (state) cells. Assign a set of chromosomes and DNA in the early phases of meiosis, if we are going to vivify gametogenesis, as a result of which spermatozoa and egg cells are established - status cells (gametes).

It infects a cell, in 4 chromosomes. Try to independently describe the phase and stage, through which you will pass in the course of meiosis. Speak and sound the set of chromosomes in the skin phase.

Remember, before meiosis, the background of DNA is seen in the synthetic period. Through the chain on the cob of meiosis, change the number - 2n4c (4 chromosomes, 8 DNA molecules). I wished I wanted to write 4n8c, but the wrong one!) And our vikhidna clitina is diploid (2n), not tetraploid (4n);)

Now, it’s an hour to discuss the biological significance of meiosis:

• Adjustment of the constant number of chromosomes in all generations, taking into account the subset of the number of chromosomes
• The breeders of the crossing over determine new combinations of genes, take into account the genetic versatility of the gamete warehouse
• Offspring with new signs - material for Evolution

Mitosis and meiosis are young only in eukaryotes, but what about bacteria? The stench of wine is a cheap way to share a single bed over the two. It’s not just bacteria, but a number of nuclear organisms: amoebi, infusoria, euglena zelenoi.

With friendly minds, the skin gets 20 chilines. If you don’t think you are friendly, then it’s more than an hour to go to the growth and development, accumulated living talk... Intervals between the podilamy, who have come up.

Amitosis (as a walnut Ἀ - part of the list і μίτος - thread)

The method of direct submission of the cell, in which case it is not possible to establish the spindle for the subtype of the identical growth of chromosomes. The clientele go on without a middle way of the constriction;

Amitosis grows in crayfish (chubby) cells, fiery changes, in old cells.

© Yuriy Bellevich

This article was written by Bellevich Yuriyam Sergiyovich and his intellectual power. Copy, extended (including copying on the other sites and resources in the Internet), if only for information and information without the prior legality of the legal student, be transferred according to the law. To reject the materials of the statty and the permission of the victorious, be vicious, be a weasel, until

mitosis- the main way of growing European cells, with any number of children being raised, and sometimes growing among daughter cells of decaying material.

Mitosis is an uninterrupted process, in which one sees chotiri phases: prophase, metaphase, anaphase and telophase. Before mitosis, preparation of the cell is carried out until the end, or interphase. The period of preparation of the cellini before mitosis and vasne mitosis is stored at once mitotic cycle... aim lower short characteristic phases of the cycle.

interphase to be stored in three periods: presynthetic, or postmytotic, - G 1, synthetic - S, postsynthetic, or premitotic, - G 2.

presynthetic period (2n 2c, de n- the number of chromosomes, s- the number of DNA molecules) - growth of cells, activization of processes of biological synthesis, preparation before the coming period.

synthetic period (2n 4c) - DNA replication.

postsynthetic period (2n 4c) - preparation of cells for mitosis, synthesis and accumulation of energy and energy for the potential growth, increase in the number of organoids, basement of centroids.

prophase (2n 4c) - dismantling of nuclear membranes, the distribution of the center of the cells to the lower poles of the cell, the formation of the spindle threads under the bottom, the “development” of the nucleus, the condensation of two-chromosome chromosomes.

metaphase (2n 4c) - vibrating the maximally condensed two-chromatic chromosomes in the equatorial area of ​​the clitin (metaphase plate), attaching the spindle threads one tip to the centroles, and the smallest ones to the centromere of chromosomes.

anaphase (4n 4c) - the distribution of two-chromatid chromosomes on the chromatid and the distribution of the cichs of the sister chromatids to the opposite poles of the cithin (with the whole chromatids they form independent one-chromatid chromosomes).

telophase (2n 2c in dermal daughter cells) - decondensation of chromosomes, establishment of a group of chromosomes of nuclear membranes near the skin group of chromosomes, loss of spindle threads underneath, emergence of a nucleus, growth of cytoplasm (cytotomy). Cytotomy in the cultivated cells is attributed to the rakhunok of the furrow of the day, in the growing cells - for the rakhunok of the clit of the plate.

1 - prophase; 2 - metaphase; 3 - anaphase; 4 - telophase.

Biological significance of mitosis. We settled in as a result of the method of raising our daughter's cells to genetically identical mothers. Mitosis is responsible for the stability of the chromosome set in the row of generations of cells. To lie in the basis of such processes, such as growth, regeneration, stateless reproduction and in.

- tse special way as a result of the transition from the diploid cell to the haploid one. Meiosis is stored in two last days, which is the front of a one-time replication of DNA.

Perche meiotic rospodil (meiosis 1) to be called reductive, some of them are often increased by a change in the number of chromosomes in a different way: from one diploid cell (2 n 4c) Two haploids (1 n 2c).

interphase 1(On the cob - 2 n 2c, In kіntsі - 2 n 4c) - synthesis and accumulation of words and energy, necessary for the health of both children, increasing the number of cells and the number of organoids, basement of centraloles, replication of DNA, which will be completed in profile 1.

prophase 1 (2n 4c) - dismantling of nuclear membranes, the distribution of the centroles to the lower poles of the cell, the formation of the spindle threads underneath, the “development” of the nucleus, the condensation of two-chromosome chromosomes, the conjugation of homologous chromosomes and crossing over. con'yugation- the process of approximation and interlacing of homologous chromosomes. A pair of homologous chromosomes is called bivalent... Crossover - the process of exchanging homologous dylancs and homologous chromosomes.

Prophase 1 is growing at the stage: Leptotene(Completed DNA replication), Zygotena(Conjugation of homologous chromosomes, approval of bivalents), Pakhitena(Crossing over, recombination of geniv), diplotena(Viyavlennya chiasm, 1 block of ovogenesis in humans), diakinesis(Thermalization of chiasm).

1 - Leptotene; 2 - Zygotene; 3 - Pakhitena; 4 - diplotene; 5 - diakinesis; 6 - metaphase 1; 7 - anaphase 1; 8 - telophase 1;
9 - prophase 2; 10 - metaphase 2; 11 - anaphase 2; 12 - telophase 2.

metaphase 1 (2n 4c) - vibudovannya bivalents in the equatorial area of ​​the bed, attaching the spindle threads one finger to the centroles, and the ones - to the centromere of chromosomes.

anaphase 1 (2n 4c) - the spread of two-chromatic chromosomes to the opposite poles of the cell (from the skin bet of homologous chromosomes, one chromosome goes to one pole, and one chromosome - to the other), chromosome recombination.

telophase 1 (1n 2c in skin cells) - the coverage of nuclear membranes about groups of two-chromatic chromosomes, growth of cytoplasm. In bagatokh roslin, clitine from anaphase 1 immediately go to prophase 2.

Other meiotic rosodil (meiosis 2) be called equational.

interphase 2, abo Interkines (1n 2c), It is a short break between the first and the other meiotic subtype, before the hour of which there is no DNA replication. Typical for tvarin klin.

prophase 2 (1n 2c) - dismantling of nuclear membranes, the separation of the center of the cells to the lower poles of the cell, the shaping of the spindle threads to the bottom.

metaphase 2 (1n 2c) - vibudovannya two-chromatic chromosomes in the equatorial area of ​​the clytin (metaphase plate), attaching the threads of the spindle with one finger to the centroles, in the middle - to the centromere of chromosomes; 2 block of ovogenesis in humans.

anaphase 2 (2n 2s) - rosodil of two-chromatic chromosomes on chromatids and distribution of cichs of sister chromatids to the opposite poles of the clitin (with a whole chromatid they form independent one-chromatid chromosomes), recombination of chromosomes.

telophase 2 (1n 1c in skin cells) - decondensation of chromosomes, establishment of chromosomes of nuclear membranes near the skin group of chromosomes, collapse of the spindle threads underneath, emergence of nuclei, growth of cytoplasm (cytotomy) due to changes in haploid cells.

Biological significance to meiosis. Meiosis is the central stage of gametogenesis in animals and sporogenesis in roslin. Being the basis of combinative ministry, meiosis will prevent the genetic development of gametes.

amitosis

amitosis- straight underneath the interphase nucleus with a constriction path without setting chromosomes, a pose that is mitotic to the cycle. Described for old, pathologically changing and adhering to the bend of the clitin. The process of amytosis of cellin does not turn into a normal mitotic cycle.

cell cycle

cell cycle- the life of a clergy from the moment she appears before her death. The obligatory component of the cell cycle is the mitotic cycle, which includes the period of preparation before the period of vasne mitosis. Krym, in the life cycle є while I calm down, before the hour of some kind of viconious functions and take away a share: a bend or turning into a mitotic cycle.

Jump to lectures №12"Photosynthesis. chemosynthesis "

Jump to lectures №14"Reproduction of organisms"

Phase G1 is characterized by the renewal of intensive processes of biosynthesis, which during the period of mitosis is quick to develop, and for a short hour of cytokinesis - to creep up. The home side of the house will grow without interruption in an hour of the whole phase. For a larger client, the critical point in the G1 phase is the so-called restriction point. When passing through the cells, internal changes occur, for which cells are guilty to go through all the onset phases of the cell cycle. The cordon between the S and G2 phases will start with a speech - an activator of the S-phase.

Phase G2 is seen as the period of preparation of cells until the ear of mitosis. Less triviality for the last period. They see the synthesis of bilks of time (tubulin) and the phosphorylates of bilks, which take part in the condensation of chromatin.

Two parallel processes take place for an hour. The process of condensation of chromatin, the formation of clearly visible chromosomes and disintegration of the nucleus, as well as the formation of a spindle underneath, will ensure the correct growth of chromosomes between daughter cells. There are two processes of spacious distribution of the nuclear envelope, as it is possible to take hold of all the problems and to collapse only in the beginning of the day. The center of organizing microtubules in a large number of animals and some growing cells is a cell center or a centrosome. In interphase cells, they grow from the side of the nucleus. At the central part of the centrosom, two centros are roasted, one-to-one in the material along with a straight cut. From the peripheral part of the centrosome, there are numerous tubules, approved by the white tubulin. The stench is in the interphase cells, setting in the cytoskeleton. Microtubules are processed in the camp just as fast as a shvidkoy gathering and picking. The stench is unstable and constantly changing. For example, in cells of fibroblasts in culture in vitro, the average hour of life of microtubules becomes less than 10 min. On the cob mitosis of the microtubules falls off, and then renewal is repaired. A sprinkle of stench is found in the perinuclear zone, forming an exchange structure - a star. Center її osіti є centrosome. Microtubules є have polar structures, like tubulin molecules, and the smell of the smell becomes an orinated singing rank. One end of the day will be podovzhutsya in two shvidshe for the others. Shvidko zrostayuchі kіntsі are called plus kіntsіy, mostly zrostayuchі minus-kіntsi. Plus, they are directed forward at a straight line of growth. The centriole is a small cylindrical organelle with a thickness of about 0.2 µm and an average of 0.4 µm. There are nine groups of triplets of tubules. The triplet has one tubule on the other and two snuggled up to it. Skin triplet of heaps in the center of the central axis. Suspended triplets with cross-stitches. New centrioles win only a subordinate walk of the same ones. The whole process starts in an hour the synthesis of DNA in the S-phase. In the G1 period, the centrioles are distributed, so that a pair is created, on a small number of microns. Let's go to the skin of the center, in the middle part, the daughter of the centriole will be in the straight cut. The growth of daughter centers is completed in the G2 phase, the ale smell is buried in one mass of centrosomal material. On the ear of prophase, the dermal pair of centroles becomes part of the centrosome, from which the radial bundle of the microtubule comes in - the zirka. The spindles are formed one way out of one on two sides of the nucleus, flocking with the poles of the spindle underneath.

Prometaphase is repaired from a sharp drop of the nuclear envelope on the membrane fragment, which does not appear from the EPC fragments. The stench is destroyed to the periphery of the cell by chromosomes and the spindle of the bottom. On the centromere of chromosomes, a bilkovy complex is established, which, on electronic photographs, looks like a plate-like trisharov structure - kinetochore. Both chromatids carry one kinetochore each, while the spindle microtubules are attached to each other. The methods of molecular genetics have determined that the information is based on the specific construction of the kinetochore in the nucleotide sequence of DNA in the centromere region. The microtubules of the spindle, attached to the kinetochores of the chromosomes, play an even more important role, the stench is persistent, and the skin chromosome is smelled like this, so that two kinetochores bulge to the opposite poles of the bed. In a different way, microtubules change chromosomes, and their centromeres have appeared in the area of ​​the kiltini. The whole process in the cells of the borrowers from 10 to 20 min and will be completed before the end of the prometaphase. The number of microtubules tied with cutaneous kinetochores is different in different species. In humans, they are 20 to 40, in others - 1. Z chromosomes are linked plus a tiny microtubule. In addition to the kinetochorny microtubules, the spindle is placed underneath the other pole microtubules, which go from the other poles and on the squares are sewn with special tags. Microtubules that come out of the centrosome and do not turn on until the spindle go down, they call the astral stench to set the glare.

Metaphase. I borrow a part of mitose. Vaughn is easy to recognize for two signs: a bipolar structure of a spindle underneath and a metaphase chromosomal plate. The celline is relatively stable, a lot of cells can be kept in the metaphase for a few years or even days, if the spindle tubules are depolymerized with rivers. If the agent is seen, the mitotic spindle should be completed before the renewal and the cell should be completed.

Anaphase is repaired by quick synchronous splitting of all chromosomes into sister chromatids, skin cells of the kinetochore. The splitting of chromosomes into chromatids is linked to replication of DNA in the centromere region. A replica of such a small diley will take a few seconds to complete. The signal before the ear of anaphase goes from the cytosol, the dressings with the short-hour rapid increase in the concentration of calcium ions by a factor of 10. Electronic microscopy showed that at the poles of the spindle there is a purchase of membrane bulbs, rich calcium. In response to the anaphase signal of the sister chromatids, they repair the ruch to the poles. Tse is tied in the perch with shortened kinetochoric tubes (anaphase A), and then - the spreading of the poles themselves, tied with the sublimated polar microtubules (anaphase B). The process is self-hosted, on which I will order it to be sensitive to the point. In the small organisms, the additions of anaphase A and anaphase B have residual rosin chromosomes. For example, anaphase B is in the class of ssavtsi B to be repaired next to anaphase A and to end, if the spindle reaches the end of anaphase 1.5-2 times more, lower in metaphase. In the simplest, anaphase B is rewound, due to which the spindle podovzhuet 15 times. The speed of the kinetochorny tubes and the path of the depolymerization. The subunits are destroyed from plus the end, so that from the side of the kinetochore, as a result, the kinetochore is re-sup- ported at once from the chromosome to the pole. There are pole microtubules. Then, in anaphase, one sees the rise of the world and the rise of the poles in the world. Until the end of the anaphase, chromosomes grow on two identical groups at the poles of the cell.

The nucleus and the cytoplasm were tied. The role of the mitotic spindle is very important in this process. The breeding cells are already in anaphase, in the area of ​​the spindle, there is a boring time. Vona lay down with a straight kut to the next axis of the mitotic spindle. The furrow osvita is explained by the activity of the contractile ring, which grows under the membrane of the cell. It is stocked from the thinnest threads - Actinovi filaments. The swiftness of the ring is strong enough to bend the thin, thin head inserted into the cell. In the world of perishing furrows, the size of the reduced ring does not get lost, as a part of the filaments is consumed when the radius changes. As the cytokinesis of rapidity is completed, the cytokinesis gradually fall, the plasma membrane in the area of ​​the furrow shrinks. One hour in the contact zone of the newcomers, the clientele will be able to get away from the surplus of tightly packed microtubules. In the growing cells, where they have a hard cell, the cytoplasm is distributed by the path of establishing new trends on the cordon between the daughter cells. In growing cells, there is no contractile ring. A phragmoplast is formed near the area of ​​the cell, gradually expanding towards the center of the cell to the periphery, as long as the growing cell does not reach the plasma membrane of the mother cell. The membranes get angry, and the clitini started appearing.