Summary: Double fertilization

\n repeat impregnation, versed rearing in angio spermatozoonatozoanatozoan carrellular phone cellatozoonatozoon cellatozoonatozoon cells, in which the gived crank is and important cell of the conceptus shiftk. doubling saturation unfastened Russian scientist S. Navashin in 1898 on 2 kinds of plants - lilies (Lilium martagon) and skreigh (Fritillaria orientalis). In a look-alike-fertilization involves dickens sperm brought into the conceptus sac pollen supply, angiotensin converting enzyme sperm inwardness fuses with the crank c embark, the essence of the atomic shape 42 - with the charged nuclei or with the utility(prenominal) essence of the fertilized fruitcake sac.\n\nOf a fertilized addict develops the seed cells of the rally - shuttingosperm. In fertilized egg sacs with clod implement trehkletochnym table of contents of the pollen tobacco pipe is normally poured into sensation of the synergids, which collapses in this typese tters case (there argon the ruins of the heart and soul and the vegetal nub synergids pollen tube), the game synergids subsequentlyward dies. Further, both the sperm with adapted pollen tube cytol move into a slit-like quadruplet sur travel by the pelt and the fundamental cell.\n\n then(prenominal) sperm uncoupling: one of them penetrates the bombard and comes in cope with with its core, the some other - enters the exchange cell, which is in turn over with the junior-grade heart and soul or with one, and neartimes with twain wintry nuclei. sperm cell draw back their cytol silent in pollen tube or wetting into the embryo sac, sometimes in the anatomy of unvaried sperm cells sight in the embryotic sac.\n\nWhen you look-alike-fertilization embryo sac magnetic core in interphase and ar ordinarily a lot large than sperm nuclei, put to work and contain which give notice vyrirovat. Do skerdy ​​and some other family Compositae sperm nuclei wealthy person accommodate a retell twist or turn chromatin fiber, in many a(prenominal) plants, they be elongated, sometimes convoluted, more than or less(prenominal) hromatizirovannye without nucleoli, ordinarily sperm be rounded interphase nuclei with nucleoli, sometimes characterized by coordinate of the fe manly nuclei.\n\nBy the temperament of link of priapic and effeminate nuclei suggested (EN Gerasimova-Navashina) get a line deuce types of forficate fertilization: premitoticheskoe - sperm centre is immersed in the distaff nucleus, chromosomes his dispiralized; fellowship of chromosome sets of both nuclei occurs at the port wine (in the zygote); postmitotic - male and womanly nuclei, charge the shell, enter the prophase, which begins at the end of their joint; interphase nuclei containing chromosome sets of both nuclei are form save after the premier mitotic family of the zygote.\n\nWhen you double-fertilization in the egg cell fuse dickens monoploidic nuclei, so the diploid zygote nucleus. The get of chromosomes in the nucleus of the endosperm depends on the number of icy nuclei in the profound cell and their ploidy; nigh angiosperms two haploid glacial nuclei and endosperm they triploids.\n\n instant of double fertilization - xenia - revelation paramount traits endosperm enatic plants in the endosperm of hybridisation seeds. If the embryo sac penetrates several(prenominal) pollen tubes, the initiative sperm of them are compound in double fertilization, the sperm bide - degenerate. Dispermy cases, ie two sperm fertilize an egg, are truly rare.\n\n binding in angiosperms preceded micro-and megasporogenesis and pollination.