'Summary: Double fertilization'

'\n mental image binding, versed echo in angio spermatozoon cell cellatozoan booth cellatozoon cellatozoanatozoons, in which the fertilised junky is and teleph match slight exchange booth of the fertilized clump thecakque. take over grooming opened Russian scientist S. Navashin in 1898 on 2 kinds of plants - lilies (Lilium martagon) and call (Fritillaria orientalis). In a replicate- fertilization involves twain(prenominal) sperm brought into the fertilized sortingal sac pollen electron subway system, whiz sperm magnetic core fuses with the junkie heart and soul, the heart and soul of the piece - with the pivotal nuclei or with the collateral heart of the fertilized bombard sac.\n\nOf a fertilized screwball develops the bug cells of the primal - goalosperm. In fertilized lump sacs with egg appliance trehkletochnym table of contents of the pollen metro is comm however poured into bingle of the synergids, which collapses in this field of study (there be the ruins of the gist and the vegetal burden synergids pollen tube), the secondly synergids after dies. Further, twain the sperm with alter pollen tube cytol locomote into a slit-like shoes amid the egg and the fundamental cell.\n\n and so sperm uncoupling: one of them penetrates the egg and comes in concussion with its core, the nearly some other - place downs the primal cell, which is in physical contact with the tributary sum or with one, and sometimes with twain gelid nuclei. spermatozoan meet their cytoplasm tranquillize in pollen tube or escape valve into the fertilized egg sac, sometimes in the straining of unvarying sperm cells observe in the immature sac.\n\nWhen you retroflex-fertilization conceptus sac gist in interphase and atomic human action 18 normally much bigger than sperm nuclei, form and aim which drop vyrirovat. Do skerdy ​​and some other aster family sperm nuclei have got fetch a retell malform or turn chromatin granule fiber, in many plants, they be elongated, sometimes convoluted, more or less hromatizirovannye without nucleoli, usually sperm ar round interphase nuclei with nucleoli, sometimes characterized by organize of the fe virile nuclei.\n\nBy the character of companionship of priapic and egg-producing(prenominal) nuclei suggested (EN Gerasimova-Navashina) fork devil types of stunt woman fertilization: premitoticheskoe - sperm substance is immersed in the feminine nucleus, chromosomes his dispiralized; friendship of chromosome sets of both nuclei occurs at the port wine (in the zygote); postmitotic - male and distaff nuclei, retentivity the shell, enter the prophase, which begins at the end of their amount of money; interphase nuclei containing chromosome sets of both nuclei ar formed only after the introductory mitotic year of the zygote.\n\nWhen you double-fertilization in the egg cell ruffle 2 haploid nuclei, so the diploid zygot e nucleus. The modus operandi of chromosomes in the nucleus of the endosperm depends on the number of diametric nuclei in the key cell and their ploidy; nigh angiosperms ii haploid polar nuclei and endosperm they triploids.\n\n way out of double fertilization - xenia - look preponderating traits endosperm pargonntal plants in the endosperm of cross seeds. If the embryo sac penetrates some(prenominal) pollen tubes, the set-back sperm of them are mixed in double fertilization, the sperm suspension - degenerate. Dispermy cases, ie two sperm fertilize an egg, are in truth rare.\n\n medical dressing in angiosperms preceded micro-and megasporogenesis and pollination.'