Meiosis(Greek: meiosis - change) - the process of splitting the clitin nucleus from the adopted daughter nuclei, the skin from which to eliminate two less chromosomes, lower the nucleus. Meiosis is a reduction case: there is a change in the number of chromosomes in a clitin from diploid (2n) to haploid (n). Meiosis accompanies the establishment of gametes in creatures and the establishment of spores in Roslins. As a result of meiosis, haploid nuclei emerge, and with such an increase, a diploid set of chromosomes is restored.

Meiosis (scheme). As a result of meiosis, two gametes with haploid sets of chromosomes are blamed, which are separated from each other (Harnden, 1965).

Meiosis includes two successive copies. In cutaneous meiotic rosacea, there are several stages: prophase, metaphase, anaphase, and telophase.

First meiotic was called reduction. As a result, one cell with a diploid set of chromosomes becomes two with a haploid set.

Prophase I is the prophase of the first meiotic sub-line - naytrivalish. Її mentally divide five stages: leptotene, zygoten, pachytene, diploten and diakinesis.

The first stage - leptoten - is characterized by an increase in the core. The nucleus shows a diploid number of chromosomes. Chromosomes are long, thin threads. The skin chromosome is made up of two chromatids. Chromatidi can be chromomirne

Budova. Spiralization of chromosomes begins.

Under the hour of another stage of prophase of the 1st meiotic division - zygoten - conjugation of homologous chromosomes occurs. Chromosomes are called homologous if they have the same form of the world: one of them is taken from the mother, the other from the father. Homologous chromosomes are attracted and applied one to one throughout the entire period. The centromere of one of the paired chromosomes adheres exactly to the centromere of the other, and the skin chromatid adheres to the homologous chromatid.

The third stage is pakhitena - the stage of threads. Conjugating chromosomes closely adjoin one to one. Such double chromosomes are called bivalents. Skin bivalent is composed of four (zoshiti) chromatids. The number of bivalents is equal to the haploid set of chromosomes. Spiralization is farther away. Close contact between chromatids allows exchange of identical spacers in homologous chromosomes. Tse is called crossing over (English crossing over - crossing).

The fourth stage - diplotene - is characterized by the vinification of the forces of penetration. Chromosomes, which become bivalent, begin to enter one into one. Rozbіzhnist starts in the region of the center. Chromosomes are joined together at a few points. Qi points are called chiasms (Greek: chiasma - intersection), so that the points, de crossover will be. In skin chiasm, the exchange of chromatids by dilyans is observed. Chromosomes spiralize and shorten.

The fifth stage - diakinesis - is characterized by maximum spiralization, shortening and shrinking of chromosomes. The appearance of chromosomes continues, but the stench is littered with them in the bivalence of their own cycles. The nucleus and nuclear membrane are separated. The centrioles diverge to the poles.

Thus, in the prophase of the 1st meiotic subdivision, there are three main processes:

1) conjugation of homologous chromosomes;

2) the establishment of bivalent chromosomes or the absence of chromatids;

3) crossing over.

Metaphase I. In the metaphase of the first meiotic sub-half, the bivalent chromosomes are separated behind the equator of the clitinum, making up the metaphase plate. Before them, threads of the spindle are attached to the bottom.

Anaphase I. In the anaphase of the first meiotic podil to the poles of the clitin, chromosomes diverge, but not chromatids. In daughter cells, they consume less than one pair of homologous chromosomes.

Telophase I. In the telophase of the first meiotic stage, the number of chromosomes in the skin cells becomes haploid. Chromosomes are made up of two chromatids. As a result of crossing over with established chiasm, chromatids are genetically not homogeneous. For a short hour, the nuclear membrane, the chromosomes, settle down.

despiralize, the nucleus becomes interphase. Then, in a creature's cell, rozpodil cytoplasm begins, and in a dewy cell, a cell wall is formed. In bagatioch roslins, there is no telophase I, the clitin wall does not settle, there is no interphase II, clitins immediately pass from anaphase I to prophase II.

Interphase II. Tsya stage is less in creatures of clitin. Under an hour of interphase between the first and other phases, in the S period, there is no reduplication of molecules

Another meiotic subdivision is called equitable. It is similar to mitosis. Three chromosomes that make up two chromatids, chromosomes are established that form one chromatid.

Prophase II. In the prophase of another meiotic sub-half, the chromosomes are thin and short. The nucleus and nuclear membrane collapse. The spindle is settling down.

Metaphase II. At the metaphase of the other meiotic sub-half, the chromosomes have the flanks of the equator. The threads of the achromatin spindle extend to the poles. The metaphase plate is being dissolved.

Anaphase II. In the anaphase of another meiotic sub-center, the center divides and pulls along to the opposite poles of the chromatid, which are cremated one by one, called chromosomes.

Telophase II, In the telophase of another meiotic sub-half, the chromosomes despiralize, become invisible. The threads of the spindle are fading. Near the nuclei, a nuclear membrane is formed. The nuclei replace the haploid number of chromosomes. There is a subtilization of the cytoplasm and the cleavage of the clitin wall in roslins. From one vyhіdnoї kіtini utavlyayutsya chotiri haploidnі kіtini.

VALUE OF MEIOSIS

1. Adjustment of the number of chromosomes. Yakby did not blame the reduction in the number of chromosomes during gametogenesis, and stately the cells had a small haploid number of chromosomes, then from generation to generation their number increased.

2. During meiosis, a large number of new combinations of non-homologous chromosomes is established.

3. In the process of crossing over, there may be a place for recombination of genetic
material.

May all the chromosomes, like the gametes, take away the trees, which look like the father's, and the mother's chromosome. This is the great opportunity to recombine the fallow material. Whom has all one of the reasons for the sluggishness of organisms, which gives material for selection.

Meiosis - a way to subdue the clitin reduction , then. 2-fold change in fertility (transition from diploid state to haploid state). This is the mechanism that contributes to an uninterrupted increase in the number of chromosomes with an increase in gametes. The start of meiosis is stimulated postiyne the number of chromosomes in all generations of dermal species of creatures, roslin and mushrooms.

Biological sense - formation of state cells (gametes) with a haploid number of chromosomes.

Meiosis is necessary for the diversity of the genetic structure of gametes, ensuring 2 of 3 mechanisms combinative timidity (3rd filling). Zavdyaki they will have different offspring with state reproduction of organisms.
- crossing over in prophase1, as a result of which new combinations of genes are formed
- independent chromosomal distribution in anaphase1, which ensures the safety of the birth of the mother's and father's gametes.

Phase meiosis

1) Interphase with the replication of DNA molecules

2) Perche reduction rose to a change in fertility

3) Interkinesis : interphase without synthetic period, so without DNA replication

4) Friend equation shared the number of chromosomes and DNA

1) Reduction footer

Prophase 1 - 2n4s
Chromatin spiralizuetsya, chromosomes are established. Vіdbuvaєtsya conjugation - Close proximity of homologous chromosomes, so that they merge in pairs, establishing bivalence / zoshity. Dali go crossing over – exchange of conjugating homologous chromosomes between non-sister chromatids, which leads to genetic recombination. The nuclear membrane disintegrates, the centrioles diverge to the poles, and a spindle is formed below.

Metaphase 1 - 2n4 c
osvita metaphase dressing from bivalents, like vishikovuyutsya over and under the equatorial plane.

Anaphase 1 - 2 * (n2 c)
Homologous chromosomes diverge to different poles of the cell. There is a change in the number of chromosomes - reduction .

Telophase 1 -n2 c
Chromosomes are made up of 2 chromatids. The nuclear envelope, the nucleus, and then cytokinesis are established. Two daughter haploid cells are established.

2) Equation podіl

Prophase2 – n 2s
Chromatin condenses to form chromosomes. The nuclear membrane is falling apart, the nucleus is breaking down, the spindle is being settled down.

Metaphase2 – n 2s
Chromosomes are vishikovyvayutsya in the equatorial plane, the center of the threads of the spindle below. Metaphasic payment perpendicular meiosis1.

Anaphase2 - 2*( nc )
The centromeres are subducted, the threads of the spindle pull the sister chromatids to the other poles of the cell. A chromosome is made up of 1 chromatid. Despiralization of chromosomes begins.

Telophase2- n h
The spindle podіlu znikaє. Chromosomes despiralize : swell, their contours become fuzzy. A nuclear membrane is formed near the skin from two groups of identical chromosomes. They are nuclei.

Mitosis
One Rose: Equation	Two gifts: reduction and equation
In metaphase behind the equator vibudovuvayutsya dvoromatidnye chromosomes.	In metaphase 1, behind the equator, there are pairs of homologous chromosomes: bivalence/zoshity
	Conjugation and crossinover in prophase 1
	Recombination of the fall material
Mіzh rozpodіlami ide replication of DNA pіd hour of the synthetic period of interphase.	Between 1st and 2nd, there is no DNA replication, because in interkinesia during the day synthetic period
Two diploid cells are established, identical to one, one to the mother	Chotiri haploid cells are becoming established

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How many periods do you see in the development of state clitin? Describe how the period of maturation (meiosis) passes.

In the process of gametogenesis (the establishment of state cells) there are several stages.

1. The period of reproduction is characterized by a mitotic distribution of the first stages of cells; your own number is increasing.

2. The period of growth is growing in the case of increased growth of cells. For example, during interphase I, DNA reduplication is observed. The clitin formula is 2n4c.

3. Period of maturation (meiosis). Under the hour of meiosis, the cells are subdivided into two.

After the first meiotic (reduction) period in daughter cells, there is a change (reduction) in the number of chromosomes in 2 times.

Prophase I. Cellin formula 2n4c. Go DNA spiralization. Chromosomes shorten and sweat, they become visible like long thin threads. Conjugation of homologous chromosomes is observed. Conjugation is called the process of exact and close approximation of homologous chromosomes, when the skin point of one chromosome joins with the second point of another homologous chromosome. Homologіchnі - tse pairs of chromosomes, however, for common, scho to avenge in the same loci of allelic genes, scho to match for the same signs themselves. Chromosomes are utrimuyuyutsya one white one for the rahunok z'ednannya z'ednannya, scho guess zastіbku bliskavku. The half is adorned with white threads for sweats in the free days. As a result of conjugation, a bivalent (tetrad) is established, which is formed from several chromatids. Crossing-over can occur between homologous chromosomes - exchange by homologous dilyans. The ability to crossover for the skin chromosome is more than 50%. When this happens, two recumbent, non-sister chromatids are exchanged. As a result of crossing over, the skin chromosome appears to be folded from one chromatid with an invariable set of genes and the other - from recombined genes (in the warehouse of the bivalent, all chromatids are different). The spiralization of chromosomes is strengthened, the s-pomіzh of them is blamed for the forces of separation. The stench is littered with po'yazanimi at the places of crossing-over, de chiasmi (crossover) is settled. In the world of stronger spiralization, that force of chiasm shifts to the ends of chromosome arms, and terminal chiasms are established.

Metaphase I. Spiralization of chromosomes reaches a maximum. Bіvalenti vishikovuyutsya behind the equator kіtini. At the equatorial plane lie the terminal chiasms, and the centers of the homologous chromosomes are turned up to the different poles of the cells, to them the spindle is attached to the bottom.

Anaphase I. The divisions of the terminal chiasms develop and the homologous chromosomes from the bivalent begin to change to the different poles of the clitin.

As a result of the first meiotic subdivision, one chromosome from the skin pair appears in the skin daughter cells. The haploid cells with the formula 1n2c are utibilized.

Interphase II is short, DNA replication is not observed. There is a reparative synthesis of DNA, directing the repair of possible damage to the structure of DNA, which caused the process of crossing over.

II meiotic rozpodil - ekvatsiyne (zrivnyalne). Vono polagaє in the given u vіdpovіdnіst іlkostі іlkostі chromosomal set of DNA and protіkaє mitozu type. In anaphase II, sister chromatids, after under the center, become independent chromosomes and begin to move to different poles of the clitin. As a result of the II meiotic division of the dermal haploid cells (1n2c), two daughter cells with the formula 1n1c are established.

4. The period of molding is more important in the case of a special clitinous form and remoulding, necessary for specific functions.

Meiosis is a special kind of rozpodіlu kіtin, the result of which is the establishment of gametes - the state of the clitin with a haploid set of chromosomes. Vin is composed of two subdivisions - reduction and equation. In skin division of meiosis, as well as in mitosis, prophase, metaphase, anaphase and telophase are distinguished. Chromosome replication stops during periods S-interphase, which precedes meiosis I. At this stage, cells that divide are not yet determined to meiosis. Prophase I divided into sprat stages: leptotene, zygoten, pachiten, diploten, diakinesis. Leptotena(Stage of thin threads), thin twisted threads of chromosomes appear. Zigotena- conjugation of homologous chromosomes occurs, the synaptonemic complex is established, which enters the bivalent warehouse. At the crossroads of the chromatids, there are developments and exchanges of their delyanok - crossingovenr. Pachytene(Stage of threads) is characterized by a haploid number of bivalents. At this stage, there is a good memory of chromoly babies of chromosomes. AT diplomacy the structure of bivalents and warehouses of skins, of which chotiri chromatids, is most clearly visible. At this stage, homologues begin to appear and become commemorative chiasms. In diploteny, there is a greater spiralization of chromosomes, the lower stage of pachytene. AT diakinesis spiralizatsiya increases, the number of chiasms changes, bivalence grows on the periphery of the nucleus. Metaphase I. The nuclear membrane collapses and prophase changes into metaphase. The nuclei are known. The bivalents are spread in the equatorial plane of the clitinum, shaping the metaphase plate. Chromosomes are strongly spliced ​​and shortened in case of cioma. Spiralization of chromosomes is three to anaphase I, if the chromosomes are maximally spiralized. AT anaphase I chromosomes diverge to opposite poles. Batkivska and maternal centers of skin bivalent disperse to opposite poles. There is a reduction to the center. Telophase I characterized by the resolution of the nuclear membrane and changes in the structure of the nucleus. After a non-trivial interkinesis (chromosomes do not fight), one can expect another meiosis. AT prophase II Chromosomes become more memorable. Metaphase II- chromosomes vibudovanі behind the equator, they have a clearly expressed subway structure and a great step of spіralіzії. AT anaphase II divergence of sub-central centers is observed, after which the daughter chromatids diverge to different poles. AT telophase II 4 haploid nuclei are established. Biological significance of meiosis. Meiosis-method of cell division, which underlies the reduction in the number of chromosomes: 2n → n. Weisman firstly stated that the reduction of the number of chromosomes in meiosis and further downstream lie at the basis of the change in the number of chromosomes from generation to generation. Meiosis also ensures combinative variability (significance of evolution). Chromosome fragments of different bivalents diverge in anaphase independently one in one, in order to lead to recombination of father's sets of chromosomes.

Vidminnosti between mitosis and meiosis. In the prophase of mitosis, compactization of chromosomes occurs, meiosis - more conjugation of homologous chromosomes - the adoption of bivalents, recombination. In the metaphase of mitosis, there is a shift in chromosomes near the equatorial plane, meiozabivalence. Anaphase of mitosis - expansion of sister chromatids to the poles; meiosis - independent distribution of homologous chromosomes to poles, which are included in different bivalents. Telophase of mitosis formation in clitinum of two identical diploid nuclei. Meiosis is established by 4 haploid cells.

B. 9. 25. Zagalna characteristic of moss-like, their life cycle. Viddilu system. Moss-like walks. Mokhovidni - a great group of great roslins, which are already vibrating for the splendid budova. In the world of theirs, there are close to 25 thousand. vidiv. In the midst of the greater roslins, for a bunch of sights of the stench, one sits another place after the flowers. Mokhovidni are an old group in the realm of roslins. May all the stink - bagatorichnі roslini. Sound moss stunted: their height swells in decals of millimeters up to 20 cm. Among the moss-like ones, two great classes are seen - Pechenochnik and Leaf-stem mosses.

In liverworts, the body is represented by a flattened green flat layer. In the leaf-stem moss, the stems and fine green leaves are clearly visible, that is, the frogs. Tі іnshі mаut rhizoids, like dredging water from the soil and thickening dews. Mustaches of bryophytes are characterized by a significant simplicity of the inner life. In their types, the main and photosynthetic tissues, ale, conductive, mechanical, reserve and curvature tissues are daily. It is characterized by superiority in the cyclic haploid gametophyte over the diploid sporophyte. Individual life of moss-like super-sprouts. When swollen, the superchka bursts, and the intin at once from the superchka swells up at the visible papilla, which dilyachis gives an ear of either a single-row thread, or a single-ball plate that carries rhizoids. The first stage of the gametophyte is the stage of protonemia. It divides into a green, asymptomatic part - chlorinema, that barren subterranean part - rhizoderm. The epidermis of thallus and leaf-stemmed moss-like is spared cuticles and typical progenitors, the ductus system lacks sieve tubes and tracheids. It’s not so physiologically as it is physically: zavdyaks of capillarity, hygroscopicity, swelling. Pokhodzhennya is attributed to the end of the Devonian, the ear of the Carboniferous, and divided into 3 classes - Liverworts, Anthocerotos and Leaf-stem mosses. The classification is based on the life of the body, gametophytes, the peculiarities of the life of the rhizoids, the nature of the opening of the box and the geographical expansion. The leaf of the marchantia is flat, flattened at the look of the spades, the beast thallus is covered with a single-spherical epidermis with produchi. The photosynthetic tissue is lined on the chamber with partitions. The leaf is firmly attached to the substrate for additional rhizoids. On the male gametophytes, the antherids are located on the upper side of the base, and on the female gametophytes, the archegonium is ruffled on the lower side of the base. After zaplіdnennya z zygote, which has settled down, sporophyte develops at the look of the box on a short nizhtsі. Before ripening, the superchick at the box has a reduction hem, the superchicks in sporangia are fluffed up with special threads - elastomers and names. Sprouting superchicks give the cob of a haploid gametophyte in what looks like lamellar protonemia.

26. Interaction of neurons in nerve centers. Interaction between the processes of awakening and galvanization. Understanding about the reflex and the reflex arc. Mono- and polysynaptic reflection. The power of the nerve tissue to transmit zbudzhennya sound conduction. The damage is carried out along the nerve fibers in isolation and does not move from one fiber to another, which is why the membranes are shifted, so that the nerve fibers are damaged. The basis of the awakening is the change in the concentration of ions on both sides of the membrane of the nerve cells. The activity of the nervous system may have a reflex character. In the case of a reaction to teasing, stimulated by the nervous system, it is called a reflex. The way, like a nerve stimulus, is received and transmitted to the working organ, is called a reflex arc. Vin is composed of 5 factors: 1) receptor, which receives stimulation, 2) sensitive (excited) nerve, which transmits excitation to the center, 3) nerve center, deexcitation intermingles with sensitive neurons on the rukhovi, 4) rudimentary (external) nerve, scho carry zbudzhennya from the central nervous system to the working organ; 5) a working organ that reacts to otrimani razdratuvannya. The process of galmuvannya is a proliferating awakening: wine is taken up by diyalnist, easing the change of guilt. Damage in some centers of the nervous system is accompanied by galvanism in: nerve impulses that reach the central nervous system can interfere with other reflexes. Offending processes - awakening and galmuvannya - mutually pleasing, which ensures the benefit of the organs and the whole organism as a whole. For example, at the hour of walking, the shortness of m'yazіv zginachіv and rozgіnachіv is rushed: when the center of the zginanіv is awakened, the impulses are direct to the m'yazіv zginаchіv, at the same time the center of the zginаnіnіа galmuієі not sending impulses to the center of the zginаchіv, in order to stop, in order to stop For the purpose of their functions - receiving information, processing and transferring the rukhovy impulse to the visceral organ - the growths of nerve clitins are made up of neurons and in. clitins especially from the floor - synapse. When a signal is needed before the end of the axon, there is a chemical wave, as it calls for arousal or galvanization in the auscultator. Such substances are called mediators, they can be seen, for example, acetylcholine, norepinephrine and others.

27. Morphology and functions of clinal forms of fluffy tissue. Reticulin, elastic and collagen fibers. Microscopic budova, physical authority, chemical warehouse. The tissue is good, in the yakіy kіtin it is still visible richly, and the interklіtinn is not so rich in fibers. fluffy and comfortable fabric. Won to go to the warehouse of rich organs, zapovnyuє promyzhki between bagatma organs. The fluff is a good fabric with a large number of carelessly ruffled elastic and collagen fibers, like walking in the most manipulative directions. Between them and plates of amorphous in-va, cells are growing: fibroblasts, histocytes, adventitial cells, less post-fat, pigment, plasmatic and different types of leukocytes. The fabric warehouse is inconsistent. What does it mean, in a first way, to the unequal behaviors of clitin, some of them develop from the west. fabrics, and partly consumed from the bloodstream; in a different way, an unperturbed development of clitins, on the basis of which the stench can be at different stages of differentiation, thirdly, a serpentine kіlk.

Fibroblast - basic. clit. shape of the connective tissue. Small vityagnut clitins from dozhins. sprouts. Take part in the established intermediate in-va connective tissue, establish scar tissue in case of injuries. They envelop that third-party body in the form of other fabrics.

Histiocyte is a post-clinic form of healthy tissue. Mayut sharply okreslenі contours. Chi zdatnі change the form. They are called “bloating clitins of peace” because during the ignition process in the organism, the histocytes actively move until the middle of the fire from the sustantial cells of the day. tissues (turn into macrophages).

The adventitial clitinis are strongly droopy and have short, thin buds. Stink less for fibroblasts. Tse poorly differentiated cells of the connective tissue, which can develop in different directions. Tsі kіtini serve as a dzherel osvіti raznih forms of own. connective tissue, tendon, cartilage. Krim perekhovanih at Rikhl. connective tissues present fat, pigment, plasma cells.

Reticulin fibers lie on the surface of the clitin like primitive ones. They are made up of submicroscopic threads - fibril - protein to collagen, laid at the interfibrillar in-in. Reticular tissue takes part in hematopoiesis.

Colagen fibers - are made up of fibrous protein collagen - a fiber that does not anastomose between itself, but goes parallel to one another. With direct forces, as if to stretch the fabric, you may have a late swagger, tk. are made up of thin collagen fibrils. Colagen fiber - a bunch of fibrils of absolutely the same comrade, zanuren in fibrillar cementing in-in, the stench of mitzna and may not stretch. Functions: support, filter, because can adsorb on the surface of speech. Collagen fibrils are made up of thin protofibrils (filaments) saturated with collagen molecules. The skin period, which may be in 640 about A, consists of two zones - light and dark. The collagen molecule is made up of three identical polypeptide strands, including amino acids. MM thread 120000

Elastic fibers are homogeneous, they anastomose regularly. z іn., establishing a single elastic mesh, easily stretching that german for opening. The stench is made up of threads of protein to elastin (proelastin), but it can also be used after a cementing speech rich in carbohydrates (elastomucin). In the elastic fiber, the middle axial thread of protein molecules is separated, and the outer ball of protein molecules bound by polysaccharide. The greatest folding of elastin fibers is at the walls of the great arteries, and the stench can look like thick membranes with a collagen-like middle. From the surface of the membrane, the membrane is dressed with a mucopolysaccharide clutch with an active exchange of speech.

B.10. 28. Significant character of fern-like. Pokhodzhennya leaf fern. Tipi stele. Features of molding sporangia. An ancient group of spore-growing roslins, a geological century similar to Horsetails. Vikopnі forms v_domi z Devon. Rozkvit їх letters u carbonі. Maє great leafing - vay. zdebіlsh bagatorazovo rossіchenі, feathers became in the aftermath of the forgiveness of the great eagles. Leafing through the trival hour, let the upper growth grow, weave the petiole and the shawl. The plate is attached to the axis or rachis, which represents the continuation of the petiole and the corresponding head vein of the leaf. The stem is large and short, horizontally splayed near the rhizome, adventitious roots appear on the lower side of it. Cambodia is typical, they have no secondary trees, the wood-like forms are lined with sclerenchymal sheathing around the stem bundles, which are carried out. Sclerenchyma is present and in roots. In the life cycle, the sporophyte prevails - the bagatoric roslin has grown. Life cycle: sporangia develop on the underside of a green leaf on special spore-bearing sori or on a specialized leaf. The placenta is attached to the arcus. In bagatioh ferns, sorusi are formed from a swollen bed - a receptacle, to which sporangia are attached for help. Calls of sporangia protection special. clitins that cover, molded as a result of macular growth of the placenta, or the surface of the tissue sheet. In case of subsyhannia, sporangia of veins develops in the areas of thin-walled cells. Superchki hang and develop gametophyte like a sprout. Gametophytes of both articles, green, heart-shaped forms live on the surface soil. On the lower side of the gametophyte, archegonia and antherids develop. Antherids are found in the basis of the lamina of the overgrowth and ripen earlier. Trochs later on the top of the shawl develop archegonia. Such an unevenness of the development is contagious. A zygote is formed from a zaploid ovum, which gives an ear of a diploid germ from which a diploid sporophyte is formed. The stench also reproduces vegetatively, with the help of the vines, which are established on the leaves, stems, and roots. Divided into 7 classes (Unovnikov, Maratiev, Polipodiev).

29. Spinal cord. Zagalna budovi scheme. Development of afferent, afferent and intermediate neurons. Conductive system of the spinal cord; reflex function. The spinal cord is phylogenetically the oldest branch of the CNS. The spinal cord is ruffled at the spinal canal. Vіn maє vglyad tube, scho to enter the brain, from the empty - the central canal, the back of the spinal cord. The spinal cord is composed of white (sound) and gray (in the middle) in-va. Sіre in-in folded s tіl nerve cells and dendrites and maє on the transverse view of the shape of the barrel, in the direction of the "creel" that there are two anterior and two posterior horns. At the anterior horns, motoneurons are transferred, which enter the rukhovi (chi central) nerves. The posterior horns include nerve cells, which are suitable for sensitive fibers of the posterior roots. Standing next to each other, the anterior and posterior roots are formed by 31 pairs of loose (ruffled and sensitive) cerebrospinal nerves, the skin of which, once they exit from the spinal cord, are divided into ventral and dorsal (in humans, anterior and posterior) roots. The skin pair of nerves innervation of the first group of m'yaziv and the other type of shkiri. More in-established by the growths of nerve clitins (nerve fibers, axons), united by the conduits. In the siromu, the front, back and side horns are separated. At the warehouse of the dorsal roots of the spinal cord, the axons of sensory neurons protrude, the bodies of which are located in the ganglia of the dorsal (posterior) roots, which are spread over the cords from the spinal cord and ventilate. In the spinal cord, the ci axons are straight at the dorsal horns of the gray in-va, and they make synapses with interneurons (interneurons). Remain, with your own heart, synapse with motor neurons, which in the ventral (anterior) horns of the spinal cord, the axons of which fill the spinal cord at the warehouse of the ventral roots. In the thoracic, upper transverse, and sacral spinal cords, the sire is equipped with flank horns to avenge the bodies of preganglionic neurons of the autonomic nervous system. More in-in are composed of bundles of nerve fibers, which establish ducts (tracts), which go through the gray in-va of the spinal cord to the brain and form a connection between the spinal nerves and the brain. The upper paths carry sensory information to the brain, while the lower paths from the brain to the spinal cord carry bad signals. The function of the spinal cord is contracted in cioma, which serves as a coordinating center for simple spinal reflexes (on the knee reflex) and autonomous reflexes (for example, the speed of the sciatic michur), and to create a connection between the spinal nerves and the brain. The spinal cord has 2 functions - reflex and conductor. The skin reflex is carried out for the help of a strictly singing division of the central nervous system - the nerve center. Nervous center is called the congestion of nerve clitin, rotting in one of the brain cells and regulating the activity of any organ or system. For example, the center of the knee reflex is found in the transverse segment of the SM, the center of the cut is in the crotch, and the center of the expansion of the chin is in the upper thoracic segment of the SM. The nerve center is made up of intercalated neurons. The new information is processed, as it comes from different receptors, that impulses are formed, which are transmitted to the visceral organs. Another function of the spinal cord is conductor. Bundles of nerve fibers settle more in-in, strengthen the differences between the spinal cord between themselves and the cephalic brain behind the spinal cord. Separate the upper paths, which carry impulses to the brain, and the lower ones, which carry impulses from the brain to the spinal cord. According to the first impulses, which are caused in the receptors of the shkir, m'yazyv, internal organs, are carried out along the spinal nerves in the posterior cortex of the spinal cord, are received by sensitive neurons of the spinal nodes and the stars are direct or in the posterior horns of the spinal cord, or in the warehouse, reach the stovbur, and then we will kori the great pivkul. Downstream paths to carry out the awakening from the brain to the rukhovy neurons of the spinal cord. Sounds of arousal are transmitted along the spinal nerves to the visceral organs. The activity of the spinal cord is changed under the control of the brain, which regulates the spinal reflex.

Reduction of the number of equals.

As you can see, a number of important authorities of the stationary camps can be manifested, influencing the authority of the right parts of the differential equalities, and without going into the exact analytical solution. However, this approach gives good results with the previous models, which are made up of a small number, usually two equals.

It was understood that it is necessary to correct all the changing concentrations of intermediary speeches, which take part in simple biochemical cycles, the number of equalities in the model appears even greater. Therefore, for a successful analysis, it will be necessary to reduce the number of equals in the current model of that link to a model that is made up of a small number of equals, yak, prote, to reflect the most important dynamic power of the system. The change in the number of equals cannot be sufficient - it can be adjusted to the ob'ektivnymi laws and rules. In a different way, it is great to waste some of the original authorities of the object, so as not only to destroy the model that is being looked at, but also to destroy the inadequate modeling of the biological system.

Shvidki and povіlnі zminnі.

The reduction of the number of equals is based on the principle of a narrow space, or else it is applied to all changes in folding systems on a swede and a floor. Let's wonder who has the right principle.

The heterogeneous nature of the organization of biological systems is manifested both in the structural and in the dynamic aspect. Different functional processes, other than metabolic cycles, vary greatly in their characteristic hours (t) and speeds. In a healthy biological system, the processes of enzymatic catalysis (t ~ 10"" - 10 6 s), physiological adaptation (t ~ second-quiliny), reproduction (t in dekilkoh hvilin and more) occur at the same time. To be at the mezzani of one horde Lancyuguaga, the reactive Zapzhdi є nyibilsh is nibilni і nyshvidshі, the basis for the health of the principle of the university of the saga, the reaction of the reaction of the navigy, The final hour of the process practically changes with the characteristic hour of this narrow month. In this way, although complex biological processes include even a large number of intermediate stages, their dynamic powers are equal to a small number of the most important lanoks. Tse means that the follow-up can be carried out on models, which means less equal. The most important stages are characterized by changing values, which change to a greater extent, and to the most common stages - by a small amount. Tse maє deep meaning. If we add some sort of rank to such a system (we’ll add to it like a cloud), then we’ll have to change the concentration of speeches, which will mutually change, start to change. However, it is necessary to take into account the situation with different speeds for different speeches. At the stable system, the shifts change the locks, then turn quickly to their cob values. Navpaki, more changes are being changed in the course of transitional processes, so as to determine the dynamics of changes in the entire system.

In real minds, the system of recognition of the names of “posts”, as they bring to visible changes of the most important changes, the proteo of the changes will be more important to change their stationary values. So, for swedish changes in the differential equals, which describe their behavior in the hour, you can write down the equalization of algebra, which assigns their stationary values. In such a way, the reduction of the number of differential equals of the new system is reduced, as now we turn on more than enough changes, which lie at the right time.

Suppose we have two differential equalities for two Xі at like that

de BUT " 1 is a large value.

Tse means that tvir AF(x, y) - a great value, henceforth, the speed of change is also great. Zvіdsi

next, sho - swidka is changed. Let's divide the right and left part of the first equal to BUT and we introduce a value. Take away

It can be seen, WHAT AT? -> Pro

Otzhe, differential equal for change X you can replace the algebraic

in which case x takes a stationary value, which should be deposited as a parameter, so x = x (y). Whose senses have a lot of change atє keruyuchim parameter, zamіnyuyuchi that you can carry out the coordinates of the stationary point x(y). In the induced butt (1.18) of a flow-through cultivator, the role of such an important parameter was dominated by the value that 0- Shvidkіst nadkhodzhennya kіtin. Povіlno zm_nyuyuchi tsyu value, michaly vyklikali vizno svydka installed in the system of stationary concentration of clitin (h- Shvidka is changed). Adding to (1.18) equal, what would describe the change better i p at the hour, we could take a new description of the system with the improvements of the shvidkoy (h) and the correct (y,) change.

In addition, the biological system has the role of the university. the full stage can win over the different lanks of the lancer fallowly in the minds of the best minds. Let's look at, for example, the nature of light

Rice. 1.6. The occurrence of dryness of the sight of sour (z 0,) according to the intensity of lightening (/) during photosynthesis

curve of photosynthesis - fallow of freshness of sight of sour in the light of light intensity (/) (Fig. 1.6). On the dealership OA tsієї curves in case of lack of light in a narrow space of the whole process of photosynthetic vision 0 2 є cob photochemical stages of claying and transformation of the energy of light in the pigment apparatus. Significantly, it is practical not to lie on its own during the process. Moreover, at low lightness, the speed of photosynthesis is high, and the speed of vision 0 2 seems to change little with temperature in the physiological range (5 - 30 ° C). On this distance of light curves, the role of the swedish change plays the role of dark processes in the transport of electrons, as it easily reacts to changes in the minds of lightening and the current of the electron flow in the reaction centers of the fogosynthetic apparatus at low light.

However, for more high intensities at the station LV the light curve of the limiting stage melts already dark biochemical processes of electron transfer and water distribution. At the minds of the great / dark processes become a narrow space. The stench cannot cope with the strained flow of electrons, which goes like a pigment apparatus with great illumination, which leads to a light intensity of photosynthesis. At this stage, through the enzymatic nature of the tempo processes, the temperature increase leads to an increase in the speed of photosynthesis (seeing sourness) in the minds of the light intensity of photosynthesis. Here the role of the main stage is played by dark processes, and the swedish stage is played by the processes of energy migration and transformation in the reaction centers.