Khathi amaseli proliferating. Ukukhula ekwandeni amaseli

Mhlawumbe akukho kaningi wafunda esikoleni biology imiqondo zohlelo kuka iseli. Kusukela lapho baziswa 5 kumlando ekilasini zemvelo, bese baphathwe 6 replicates njengoba zinhlobo futhi cell division izindlela zalo. Emabangeni 7 futhi 8 watadisha kusukela iphuzu Ngenxa isitshalo, isilwane futhi labhalwa umuntu. Ibanga 9 kuhlanganisa ukucabangela izinqubo zangaphakathi okwenzeka kuwo, okungukuthi, ukwakheka kwama-molecule. Ngezinye 10 no-11 kuyinto imfundiso yokuziphendukela cell, ukutholakala kanye kwemvelo.

Uhlelo yakhiwe ngaleyo ndlela ngoba lezi zakhiwo elincane, "amabhlogo wokwakha wokuphila," kukhona izakhi ezibaluleke kakhulu kwanoma iyiphi umzimba. Zonke imisebenzi ebalulekile, izinqubo, ukukhula kanye nokuthuthuka, ukwakheka - konke okuphathelene nokuphila, kwenziwe ngazo bese kuzo. Ngakho-ke, kulesi sihloko sizobheka amaphuzu ayinhloko imifanekiso, ukuthuthukiswa cell futhi umlando ukutholakala kwawo.

Ukuvula amaseli

Lezi zinhlayiya kwesakhiwo mancane kakhulu ngobukhulu. Ngakho-ke, i-ukutholakala kwawo kwakuthatha isikhathi eside futhi ukudalwa ubuchwepheshe ethize. Ngokokuqala ngqá isakhiwo solwazi of eziphilayo izicubu isitshalo wabona Robert Guk. Lokho kwenzeka ngo-1665. Ukuze bakwazi ukucabanga, wasungula microscope kuqala. Le divayisi ufana kancane ukuze yesimanje yokusondeza amadivaysi. Kunalokho, kwakunjengokungathi kuyisifo abambalwa bahlela phakathi iluphu, enikeza ukwanda.

Ukusebenzisa le divayisi, usosayensi kubhekwe isigaba kwesihlahla ukhokho. Ngokungangabazeki, lokho akubona kwakuyisiqalo ukuthuthukiswa inombolo wesayensi ahlobene eziphilayo bebonke. A sebuningini amaseli uvalwe abutting yobukhulu okungenani zilingana shape. UHooke wababiza cella, okusho "ingqamuzana".

Ngemva kwalokho wenza eziningi izinto ezazithola wavumela ulwazi sikhule, ithola bese umphumela wesayensi eziningana ezihilelekile esifundweni sawo.

1. 1675 - usosayensi Malpighi wafunda ezihlukahlukene cell ukuma wafinyelela esiphethweni ukuthi avame round noma Bubbles okusaqanda ayewenza njalo ekuphileni juice.
2. 1682 - N. Grew Malpighi waqinisekisa okutholakele, futhi naye wafundelwa isakhiwo ulwelwesi cell.
3. 1674 - Antoni van Leeuwenhoek kuvula amaseli kwamagciwane, kanye igazi isidoda isakhiwo.
4. 1802-1809 GG. -. Sh-Brissot kanye Mirbeau zh B. Lamark ukuphakamisa ukuba khona ukufana phakathi kwezicubu futhi izilwane nezitshalo amaseli.
5. 1825 - kuvula Purkinje iseli nucleus izinyoni ngokobulili.
6. 1831-1833 GG. - Robert Brown wembula khona nucleus plant amaseli bese wethula umqondo ukubaluleka kokwakheka yasekhaya, esikhundleni ulwelwesi cell, njengoba kwakucatshangwa phambilini.
7. 1839 - Theodor Schwann ephetha ngokuthi zonke izinto eziphilayo yakhiwa amaseli, kanye ukufana esidlule nomunye (cell theory esizayo).
8. Of 1874-1875. - Chistyakov futhi Strasburger izindlela cell evulekile ukubuyabuyelela - mitosis, meiosis.

Zonke okutholakele ngokwengeziwe emkhakheni wamangqamuzana izakhiwo, imisebenzi yabo, futhi indima ukwehluka emphilweni eziphilayo Kwakuseshwa ngokushesha ngenxa ukuthuthukiswa kakhulu a iqhaza ekukhulisweni kanye ukukhanyisa imishini ekhethekile.

cell division

Ngamunye iseli a lifetime enza umjikelezo iseli - nesikhathi sokuphila kwakhe kusukela ekuzalweni kuze kube sekufeni (noma division). Ngaphezu kwalokho, akunandaba, kuba isilwane noma nemifino. Umjikelezo ukuphila kwazo okufanayo, futhi ngokuvamile, ekupheleni amaseli ayo nande sokuhlukanisa.

Yiqiniso, akubona bonke eziphilayo, le nqubo efanayo. Ukuze eukaryotic futhi prokaryotic kuba bahluke, kukhona ezinye umehluko wokusakazeka zezitshalo nezilwane amaseli.

Njengoba proliferating amaseli? Kunezindlela eziningana eziyisisekelo.

1. Mitosis.
2. Meiosis.
3. Amitosis.

Ngamunye wabo imelela inani lezinqubo izigaba. Futhi zonke lezi izinqubo acacisiwe eziphilayo ezinamangqamuzana amaningi, kokubili nezitshalo nezilwane imvelaphi. Yokuzala unicellular kwenzeka ngokumane uhlukanisa e ezimbili. Okungukuthi, izindlela ukukhiqizwa kwamangqamuzana azifani. Kukhona ngisho into efana ne-cell ukuzibulala. Lokhu self-ukubhujiswa amaseli esikhundleni izinqubo sokuhlukanisa.

Njengoba proliferating amaseli, ezifana nama-bacterium, ulwelwe oluluhlaza, ezinye elula? Asexually, indlela elula: okuqukethwe amaseli is kabili odongeni iseli ezakhiwe a transverse nokukuphakamisa longitudinal futhi iseli sehlukaniswe, umzimba komama ezimbili entsha ngokuphelele ezifanayo.

Le nqubo ibizwa ngokuthi ngqo cell division. Ngibandise, namagciwane unicellular, kodwa akukho maqondana mitotic noma izinqubo meiotic ukuba. Bona kwenzeke kuphela emzimbeni eziphilayo ezinamangqamuzana amaningi.

mitosis

Ngo nezidalwa ezinamangqamuzana amaningi iqukethe siliyise ezigidini eziyizinkulungwane zamangqamuzana. Futhi ngamunye wabo sifuna umjikelezo walo wokuphila, it is kokushiya inzalo, futhi ingafi. Amaseli nokuzala sokuhlukanisa, kodwa lokhu nqubo cha bonke of them ziyafana.

isakhiwo ukuphathwa kwabathintwayo (ubheke wonke amaseli anjalo ngaphandle lwegciwane) indlela yabo ekhethelwe ukukhiqizwa kabusha noma amitosis mitosis. Kuyinto inqubo ezithakazelisa kakhulu, ethi capacious futhi eziyinkimbinkimbi, okwaholela kusukela umzali ongayedwa amaseli diploid (ngamanye amazwi, iqoqo double wama-chromosomes) ezifanayo indodakazi ezimbili wakhe nge efanayo Ukwakheka diploid.

Yonke inqubo siqukethe amaphuzu amabili ayinhloko:

1. Mitosis - ubungako bokudlulisa futhi yonke elikuqukethe.
2. Cytokinesis - division of the protoplasm (cytoplasm nazo zonke organelles yeselula).

Lezi zinqubo zenzeka kanyekanye, okuholela ekwakhekeni ephezulu grade umzali amakhophi encishisiwe ngobukhulu.

Mitosis siqukethe izigaba ezine (prophase, metaphase, anaphase, telophase) futhi esimweni saso ngaphambi division - interphase. Cabanga ngazo zonke izindlela.

interphase

Ukukhula ekwandeni amaseli Kwenziwa kuyo yonke impilo umzimba. Nokho, akubona bonke amaseli kufanele ngesikhathi esifanayo libe khona. Abanye babo bayafa ezinsukwini ezimbili noma ezintathu (amangqamuzana abomvu egazi), abanye bahlale esaphila tekusebenta (sezinzwa).

Kodwa iningi kwempilo yengqamuzana ngayinye lilondolozwe isifo okuthiwa i interphase. Lena inkathi belungiselela nokuhlukana kwamangqamuzana akha ovuthiwe, okuyinto kuthatha 90% of the time yonke inqubo.

Ukubaluleka walesi sinyathelo ukunqwabelana kwezakhi, RNA namaprotheni synthesis molecule e-DNA. Phela, ngemva sokuhlukanisa ku indodakazi ngamunye cell kumele uthole ncamashi inani organelles, izinto kanye nesidoda okunikelwe, kangakanani kwaba e unina. Ukuze lokhu kwenzeke a kabili izakhiwo ezikhona, kuhlanganise imicu DNA.

Ngokuvamile, le interphase Kwenzeka ngezigaba ezintathu:

• presynthetic;
• zokwenziwa;
• postsynthetic.

Umphumela: ekuqongeleleni umsoco, amandla kanye nezinhlayiya ze-DNA ukuze uthole okunye sokuhlukanisa izinqubo. Ngakho, lesi sinyathelo - kumane nje kuyisiqalo loko ukuthi iseli liphindaphindeke olwengeziwe.

prophase

Kulesi sigaba, izinqubo ezinkulu alandelayo ayatholakala:

• chaza ulwelwesi zasemkhathini;
• zinyamalale (kuthiwa ziyoncibilika) nucleoli;
• Ama-chromosomes e kuzobonakala ngaphansi kwe-microscope ngenxa ezimazombe (Helix) isakhiwo;
• centriole ukuhlakaza izingongolo cell, edonsa lokuphotha nokwakha ukuqoqwa.

Kulesigaba ukukhiqizwa kabusha iseli isilwane akuhlukile bonke abanye.

metaphase

Lesi sigaba kuyinto kunalokho esifushane, imizuzu engaba ngu-10 kuphela. isisekelo salo ukuthi chromatids ahlelwe senkabazwe cell. Strings lokuphotha komunye umkhawulo bambelela centriole-pole cell, nezinye centromere ngayinye chromatids. Phakathi isakhiwo zofuzo cishe akuhlobene ngakhoke kalula isilungele Ukukhipha.

anaphase

Isigaba emfushane kunazo lonke mitotic umjikelezo. Isikhathi mayelana 3 imizuzu. Phakathi nale nkathi, chromatid ngamunye uya amaseli zakhe Induku uqeda isigamu olahlekile ngaye ngokwakhe, kuphenduke isakhiwo evamile chromosome.

Nokho, kule mfundo kudinga enzyme akhethekile - telomerase. Wadlulela ekuqongeleleni yayo kule interphase.

telophase

Ngamunye isigxobo iseli livela ukuqedela impahla zaso zofuzo, okuyinto igqoke ulwelwesi zenuzi, ukwakha i-nucleus. Nucleoli ukuvela. Yonke inqubo ithatha imizuzu engaba ngu-30. Lokho impela isikhathi eside. Lokhu kungenxa yokuthi kumiswa ulwelwesi nucleolar kanye zenuzi kudinga okusezingeni eliphezulu energy izindleko futhi ukutholakala ngeziningi zezinto zokwakha - izakhi (amaprotheni, ama-carbohydrate, ama-enzyme, amafutha, amino acid).

cytokinesis

Le nqubo uqeda lonke umjikelezo mitotic. Protoplasm ihlukaniswe nge organelles ngokuqinile ngesigamu, futhi indodakazi ngamunye uthola nse udadewabo. Khona-ke ngaphesheya amaseli kwakhiwa ebamba amaprotheni (actin nemvelo) okuyinto licindezele isakhiwo yonkana kanye namantshontsho atholwa kube amabili alinganayo, kodwa amancane ngosayizi kuqhathaniswa amaseli umzali.

Kulesi sigaba, zikhona ezinye umehluko lamaseli isilwane ekubeni okusakazwa isitshalo cell. Iqiniso lokuthi amaprotheni plant izakhiwo kancane futhi actin ayiqhubeki iphila. Ngakho-ke, khekube constriction is phakathi, futhi udonga kuhlukane, nhlangothi zombili zazo uginindela is imali. Lokhu kukunika rigidity isitshalo cell, uzimele yakha udonga cell.

Ukukhula ukubuyabuyelela lamaseli sisendleleni kulandele evamile umjikelezo wokuphila: lunye, ukwakheka izicubu ayeseba izitho, umsebenzi asebenzayo nokuhlukanisa, noma ukufa.

Amagciwane Engeke Esaba amaseli bese ukwanda kwabo

On umbuzo kanjani yeseli eveza, impendulo kumele inikwe intuthuko ka kuyini. Phela, siye sacabangela izinqubo mitosis isici kuphela izakhiwo ukuphathwa kwabathintwayo. Nakuba amaseli lwegciwane ukukhiqiza kabusha ngendlela kuyiwa, noma kunalokho, meiosis.

Le nqubo luyisisekelo imisebenzi ebaluleke kangaka ekukhuleni izilwane njengoba gametogenesis, ie ukuzala. Ukuthuthukiswa germ cells Kwenzeka ngezigaba eziningana. Ngakho-ke, meiosis - nakakhulu division eziyinkimbinkimbi futhi capacious kuka mitosis.

Ukuze isitshalo cell meiosis - sporogenesis isisekelo, okungukuthi, ukwakheka kwamaseli ocansini. Iqhaza main begazi meiosis ngoba zonke izinto eziphilayo ukuthi ngenxa akha ezine haploid (nge nengxenye noma isethi eyodwa wama-chromosomes) germ cells. Kungani? Ukuze ngesikhathi sokukhulelwa (Fusion gametes esilisa esifazane) iphutha diploid zygote yokutakula entsha (bungu esizayo). Lokhu kunikeza ukwehluka kwezakhi zezinto, okuholela isakhi sofuzo inhlanganisela, ukubukeka kanye ukuhlanganiswa izici ezintsha.

Isakhiwo inqubo meiosis

Kunezigaba ezimbili eziyinhloko e meiosis: Ukunciphisa kanye equational. Ngamunye kuhlanganisa zonke isigaba esifana mitosis: prophase, metaphase, anaphase futhi telophase. Cabanga kancane ngaphezulu ngamunye wabo.

ukunciphisa division

Isiphetho sendaba: amaseli olulodwa diploid yakha ezimbili haploid, neqoqo kwesigamu chromosome. izigaba:

• prophase mina;
• metaphase mina;
• anaphase mina;
• telophase I.

On ngamunye izigaba aphindaphindwe zonke ukuguqulwa efanayo ukuthi izinyathelo abafanele mitosis. Nokho, omunye umehluko sisekhona: e interphase kungekho kabili DNA, it is nje ahlukaniswe isigamu, nazo zonke. Ngakho-ke, ingxenye kuphela ukwaziswa kwezakhi zofuzo iwela indodakazi ngamunye esitokisini. Lokhu esiphelweni kokuqala isilwane amaseli bese isitshalo ezihlobene ngokobulili.

equational division

Eyesibili division meiotic, okuphumela ekwakhiweni ngisho amabili amaseli kusuka ngamunye kulowo odlule. Manje kukhona ezine uzakwabo ezifanayo haploid, okuyinto iba ngokobulili isilwane noma isitshalo amaseli. Isinyathelo division equational: prophase II, metaphase II, anaphase II, telophase II.

Ngakho, umbuzo kanjani yeseli replicates, has a impendulo kunalokho xaka futhi capacious. Ngemva kwalezi izinqubo, njengoba nazo zonke ezinye ezenzeka ezintweni eziphilayo, kuba mncane kakhulu futhi yakhiwa sebuningini izigaba.