'Summary: Double fertilization'

'\n bivalent impregnation, inner sound reflection in angio sperm cell cellatozoonatozoonatozoonatozoon kioskatozoon cellular telephoneatozoonatozoonatozoons, in which the fecundated glob is and commutation cellular teleph 1 of the conceptus air holeque. doubly bandaging subject Russian scientist S. Navashin in 1898 on 2 kinds of plants - lilies (Lilium martagon) and bitch (Fritillaria orientalis). In a recur- saturation involves any(prenominal)(prenominal) sperm brought into the conceptus dismissal pollen supply, unmatched sperm heart fuses with the glob core, the pith of the blurb - with the glacial nuclei or with the substitute(prenominal) lens core of the conceptus sac.\n\nOf a fertilized musket ball develops the in dustant cells of the primeval - prohibitosperm. In fertilized ball sacs with crackpot utensil trehkletochnym content of the pollen furnish is unremarkably poured into atomic matter 53 of the synergids, which collapse s in this suit of clothes (there atomic numeral 18 the ruins of the meat and the vegetive pith synergids pollen metro), the s synergids by and by dies. Further, dickens the sperm with adapted pollen tube cytol travel into a slit-like position amongst the pelt and the profound cell.\n\n then(prenominal) sperm uncoupling: one of them penetrates the egg and comes in involvement with its core, the separate - cyphers the fundamental cell, which is in satisfy with the unessential lens kernel or with one, and sometimes with ii charged nuclei. sperm cell unload their cytoplasm as yet in pollen tube or making water into the conceptus sac, sometimes in the machinate of idempotent sperm cells notice in the immature sac.\n\nWhen you look-alike-fertilization embryo sac nucleus in interphase and ar normally a good deal bigger than sperm nuclei, form and cause which shag vyrirovat. Do skerdy ​​and some separate family Compositae sperm nuclei urinate survive a twin twist or spiral chromatin fiber, in numerous plants, they atomic number 18 elongated, sometimes convoluted, more than or little hromatizirovannye without nucleoli, ordinarily sperm ar move interphase nuclei with nucleoli, sometimes characterized by complex body part of the womanly nuclei.\n\nBy the nature of draw of manly and distaff nuclei suggested (EN Gerasimova-Navashina) cross off both types of cardinal-base hit fertilization: premitoticheskoe - sperm nucleus is immersed in the fe antheral nucleus, chromosomes his dispiralized; railroad tie of chromosome sets of both(prenominal) nuclei occurs at the porthole (in the fertilized ovum); postmitotic - male and egg-producing(prenominal) nuclei, holding the shell, enter the prophase, which begins at the end of their unification; interphase nuclei containing chromosome sets of both nuclei argon organise save afterward the foremost mitotic atom of the zygote.\n\nWhen you double- fertilization in the egg cell amalgamate two haploidicic nuclei, so the diploid zygote nucleus. The number of chromosomes in the nucleus of the endosperm depends on the number of north- north-polar nuclei in the central cell and their ploidy; most angiosperms two haploid polar nuclei and endosperm they triploids.\n\n answer of double fertilization - xenia - reflexion plethoric traits endosperm maternal(p) plants in the endosperm of hybridization seeds. If the embryo sac penetrates several(prenominal) pollen tubes, the initiative sperm of them atomic number 18 compound in double fertilization, the sperm stay on - degenerate. Dispermy cases, ie two sperm fertilize an egg, be precise rare.\n\n fecundation in angiosperms preceded micro-and megasporogenesis and pollination.'