Know in the cell divisions

Start now to review the first meiosis:A) prophase I Prophase:This mode is similar to its counterpart in the division indirect but stay longer and characterized into several stages, including: -Phase 1 Alqladah: LeptoteneThis stage begins nucleus and intensify inflation chromosomal material and the start of the central body composition very short strings radialThen look chromosomes Kckheot extremely long and thin organized swellings of various sizes, thereby Fathbh allChromosome form necklace studded BalhbatPhase 2 duplication ZygotenShorten chromosomes and increases the intensity and approaching each problem in pairs فيلتقي all identical كروموسومينWith each other and begin the process of double points between Alkromusuman and quickly extends to other areas,Note that a Alkromusuman from the father and one from the mother at all, this process is called bilateral double بالكروموسومات.3 Phase macrophages (Alngz) PachyteneContinue chromosomes minors and Alngz and rally around each other and show each chromosome is composed of linked Kromatid yenThe central area Centromere and each pair or a pair contains four Kromatidat and called the Quartet,Then begin the process of whirling and genuine interdependence between Kromatidin in the group and does not relate to or wrap more than two with each other.4 Phase Alanfrajah (Altdhaafeeh) DiploteneChromosomes begin to move away a little from each, Vtnfsal except areas which gets docking between KromatidThe first and last chromosome of the second chromosome transforms the second shape to form تصالبي if contact one districtOnly to form loop if contact Bmntqtin or if contact several regions.Every point of contact between Kromatidin called decussation Chiasma contact zones between Kromatidat opposite كروموسومينParticularly important in the transition and the diversity of genetic makeup as exchange parts of the sites second Alkromatid, this process is called "transit".5 stage Altnavria Owaltstatah DikanesDisharmony continues and disappears cruciate shape at this stage and keep bilateral chromosomes close togetherAnd disappear nucleolus and nucleus membrane disappear begins moving pairs of chromosomes to Planer cell areaThe filaments are organized spindle extending from the poles of the cell.B metaphase I MetaphaseLiberated chromosomes within the nucleus and be completed yarn spindle formation and lined with pairs of identical chromosomesIn the equatorial level of the cell, and each pair consists in this case of two chromosomes identical or four half-chromosomal (4 Kromatidat),Every half symmetric chromosome linked by centromere. Only natural that the number of pairs of identical chromosomes equal to half the number of chromosomes in the cell.C anaphase I AnaphaseAt this stage takes each chromosome Alkromusuman alleles in separation than other shrink yarn spindleThus turning a Alkromusuman to one pole of the cell and the second to the other pole and bringing at each pole of the polar cell halfThe number of chromosomes in cell origin (each chromosome component of Kromatidin).D telophase I TelophaseIn this phase at each pole consists of polar cell membrane surrounds nuclear chromosomes so composed Nouattan BnuetanEach containing half the number of chromosomes in the original cell then At_khasr cytoplasm until they are configuredTwo separate cells (each chromosome contains Kromatidin).Meiosis II:A complete split cells Alnatjtin of meiosis I to two new cells in a way thatSimilar to what is happening in that division indirect according to the following phases:A) prophase II rophaseB) metaphase II MetaphaseC) anaphase II AnaphaseD) the final phase of the second TelophaseA second prophase:Central body is divided into each cell to two tend to the poles of the cell where clues configuration starts spindle and the wall disappearsNucleus chromosomes show is made up of chromosomes each one consisting of a pair of chromatidLinked each Psontromer and oneB metaphase II:Tstafkhalalha chromosomes on the equatorial line of the cellC anaphase II:Centromere splits which connects Kromatidi each chromosome to each other, and thus inseparableAlkromatidan and moving away in the direction of the electrodes.D telophase II:Gather a group of chromatid (now a stand-alone chromosomes) at one pole of the cell,Then mutant تستطيل to high-twisted yarn, and composed around the nuclear membrane, and thus consisting Khalatan containing NouattanEach contain half of the genetic and the result is four cells each containing halfChromosomes in the mother cell.Ohmahalanksam reductionist:1 consists of the final output of the four respective cells genetic half dubbed the gametes (sperm, eggs).If gametophyte united with the female gametophyte produces a zygote which contains the original number of genetic traits which results in himEmbryo thus keep a fixed number of chromosomes.2 exchange genetic traits between chromosomes fixed system and connective stage of prophase I soTransmitted recipe somewhere other recipe like this process is called cross.3 recipes appear prevalent and recessive traits.












Here's division steps photographerTable of the main differences between indirect division (METOSIS)

And meiosis (MEIOSIS)

Split direct ................................................ .. .. Meiosis

Leads Elytkoan two cells are alike and Seeing ......... Leads to the formation of four cells is genetically similar.One Atdmannanksama. ...................................... Includes Anksamin consecutive ........................Not lead to halving the number of chromosomes .............. Lead to halving the number of chromosomes. ........Occurs in all members of the organism ..................... Occurs only in genital ..................Prophase relatively short Aanksm ................... Prophase long and passes through multiple stages.Aanksm to multiple stages ............................................ .............................................There is no transit operation are also not genetic ............. Characterized by the presence of the transit process and the emergence of genetic ........Pelletizing intersection points ......................................... Intersection points ........................................... ...... Centromere splits in metaphase ............. Centromere splits in the first metaphase.Takes to happen since the formation of the zygote .................. Takes to occur after puberty only in higher organismsAnd continues throughout the life of the object ............................................ .................................................. ......