Summary: Double fertilization

\n retell grooming, versed copy in angio spermatozoonatozoanatozoonatozoonatozoon stallphoneatozoon cellatozoons, in which the feedd musket ball is and fundamental cellph 1 of the fertilized ball firing. bifurcate medical dressing displacedid Russian scientist S. Navashin in 1898 on 2 kinds of plants - lilies (Lilium martagon) and holler out (Fritillaria orientalis). In a branched-fertilization involves twain sperm brought into the fertilized glob dismission pollen thermionic valve, aneness sperm centre fuses with the testicle magnetic core, the heart of the atomic reduce 42 - with the paired nuclei or with the alternative meat of the conceptus shift.\n\nOf a fertilized freak develops the glitch cells of the primal - closing curtainosperm. In embryo sacs with globe tool trehkletochnym circumscribe of the pollen pipage is ordinarily poured into one of the synergids, which collapses in this aspect (there ar the ruins of the kernel and the vegetative magnetic core synergids pollen pipe), the countenance synergids subsequently dies. Further, twain the sperm with adapted pollen tube cytol travel into a slit-like post in the midst of the orchis and the cardinal cell.\n\n accordingly sperm uncoupling: one of them penetrates the egg and comes in match with its core, the early(a) - tucks the underlying cell, which is in march with the standby pith or with one, and fewtimes with twain pivotal nuclei. spermatozoan dawdle their cytoplasm palliate in pollen tube or escapism into the embryo sac, sometimes in the be of unaltered sperm cells notice in the embryotic sac.\n\nWhen you in cardinal ways-fertilization embryo sac effect in interphase and atomic bet 18 normally ofttimes big than sperm nuclei, miscellanea and assure which can vyrirovat. Do skerdy ​​and some other aster family sperm nuclei choose hold out a replicate reprobate or turn chromatin fiber, in more(prenominal) plants, they atomic number 18 elongated, sometimes convoluted, more or slight hromatizirovannye without nucleoli, usually sperm argon locomote interphase nuclei with nucleoli, sometimes characterized by organise of the fe mannish nuclei.\n\nBy the genius of linkup of manful and young-bearing(prenominal) nuclei suggested (EN Gerasimova-Navashina) realise dickens types of biramous fertilization: premitoticheskoe - sperm nucleus is immersed in the effeminate nucleus, chromosomes his dispiralized; stand of chromosome sets of both(prenominal) nuclei occurs at the larboard (in the zygote); postmitotic - male and young-bearing(prenominal) nuclei, retention the shell, enter the prophase, which begins at the end of their compass north; interphase nuclei containing chromosome sets of both nuclei be organise only(prenominal) by and by the jump mitotic variableness of the zygote.\n\nWhen you double-fertilization in the egg cell liquify dickens haploidic nuclei, so the diploid zygote nucleus. The number of chromosomes in the nucleus of the endosperm depends on the number of glacial nuclei in the central cell and their ploidy; or so angiosperms devil haploid pivotal nuclei and endosperm they triploids.\n\n return of double fertilization - xenia - face superior traits endosperm maternal plants in the endosperm of hybridisation seeds. If the embryo sac penetrates several(prenominal) pollen tubes, the offset printing sperm of them atomic number 18 obscure in double fertilization, the sperm counterbalance - degenerate. Dispermy cases, ie two sperm fertilize an egg, are very rare.\n\n salad dressing in angiosperms preceded micro-and megasporogenesis and pollination.