Waa maxay crossover laba-hybrid ah

Xeerarka dhaxal Mendel for cross monohybrid raagayaan in ay dhacdo aad u adag oo laba-hybrid. In noocan ah foomamka waalidka dhexgalka ku kala duwan yihiin laba lammaane oo sifooyinka imaanayn.

Ka fiirso tusaale ahaan iskutallaabta dihybrid iyo xaqiijinta sharciyada Mendel. Gudbay laba nooc oo ah digir, ubax cad oo qar iska caadi ah oo ubax iyo guduud, iyo qar elongated. Dhammaan shakhsiyaadka ee jiilka kowaad lahaa ubax cad oo caadi ah garaac ah. Laga soo bilaabo tan waxaannu ku tirinnaa in midabka cad (muujinaysaa by C) iyo dhererka caadiga ah (ku qor E) - waa adag u qoreysa midabka guduudan (s) iyo garaac ah elongate (e) - recessive. Marka is-pollination jiilka koowaad ee dhirta waa kala dildillaaceen. Waayo, aawadiis of caddayn u sameeyaan nidaamka isgoyska.

cross First: P1 CCEE CCEE x

G 2Ss iyo 2Ee

F1 CCEE

The weheshiga labaad (selfing Beelaha F1) P2 x CCEE CCEE. cross Dihybrid tagaa si ay u sameeyaan 16 nooc oo zygotes. gamete kasta oo ku jiri doona hal wakiil ka la lammaane P-iyo E-E-labo hiddo. Marka hiddo C this leh jaaniska siman lagu dari karaa E ama e markeeda, iyo isku wadi kartaa leh E ama e keentay foomamka CCEE hybrid leh inta jeer ee loo siman yahay ee noocyada gamete 4: .. CE, GE, CE, ce. Obedin wada, waxay sameeyaan noolaha sida: 9 la Corolla cad oo caadi ah, iyadoo 3 elongate cad garaac 3 magenta qar caadi ah iyo magenta 1 leh qar ah elongated.

In jiilka labaad by gudbaya Beelaha gooni, foomamka waalidka dusha la mid ah, qaababka loo sameeyay isku dhafan cusub ee characters (combinative ama tirayn genetic). Tani waxay ifafaale kaalin muhiim ah in horumar ah ee wax-soosaarkooda isku cusub ee sifooyin qabsiga. Sidoo kale si firfircoon loo isticmaalaa in taranta, halkaas oo crossbreeding dhirta iyo xayawaanka kala duwan iyo eyda hagaagtay waxay fursad inay soo bandhigto noocyada cusub.

Tirada phenotypes in F2 ka yar tahay tirada noocyo. Tan waxa u sabab xaqiiqada ah in ururka of gametes kala duwan siin karaa isla sifooyinka morphological. Sidaas daraaddeed, waxaan u hesho qaybsama ee phenotype ah - 9: 3: 3: 1.

Tani crossover laba-hybrid waa suurto gal ah haddii ay hiddo xukuma ku yaalaan koromosoomyada nonhomologous. salaysan Cytological ee sida midaynta iyo dib - meiosis iyo unugyada labka iyo dheddiga. Mendel ogaaday in la sida dhexgalka ee hiddo Labada ciyaaryahan kasta oo ka mid ah sifooyinka madax banaan dhaxlay isku mid ah, si xor ah la isku daro oo dhan isku suurto gal (dhaxal madax bannaan).

All astaamaha dhaxal in Mendel dhigay hal iyo laba-hybrid weheshiga, caan-gaynta dheeraad ah oo adag. Sidaas daraaddeed, isgoyska poligibridnoe dhacdaa marka noolaha waxaa la qaaday for this Sharaf saddex ama in ka badan imaanayn muuqaalada. At qalbiga isuga this of gametes iyo qeybiyey ee macluumaad hidde yihiin sharciyada dheefshiidka oo ka madax banaan dhaxalka.

Sidaa daraadeed, waxaannu ku tirinnaa in crossover laba-hybrid ah - waxaa, dhab ahaantii, labada madax bannaan-gaarey isgoyska caadiga ah, halkaas oo mid ka mid calaamad kale waxa laga soo qaatay akoonka (monohybrid). Tani waa run, waayo dhirta iyo xayawaanka.