the fate of egg cell and polar nuclei after fertilization is polar body.
the fate of egg cell and polar nuclei after fertilization is polar body.
write the fate of egg cell and polar nuclei after fertilization?
polar body
the cells of an unfertilized ovule are 8 in number and arranged in the form of 3+2+3 (from top to bottom) i.e 3 antipodal cells, 2 polar central cells, 2 synergids & 1 egg cell. one sperm fertilizes the egg cell and the other sperm combines with the two polar nuclei of the large central cell of the megagametophyte. the haploid sperm and haploid egg combine to form a diploid zygote,the process being called syngamy, while the other sperm and the two haploid polar nuclei of the large central cell of the megagametophyte form a triploid nucleus (triple fusion). some plants may form polyploid nuclei. the large cell of the gametophyte will then develop into the endosperm, a nutrient-rich tissue which provides nourishment to the developing embryo. the ovary, surrounding the ovules, develops into the fruit, which protects the seeds and may function to disperse them.
double fertilization
if the monosporic pattern occurred, the single nucleus undergoes mitosis three times, producing an eight-nucleate cell. these eight nuclei are arranged into two groups of four. these groups both send a nucleus to the center of the cell; these become the polar nuclei. depending on the species, these nuclei fuse together before or upon fertilization of the central cell. the three nuclei at the end of the cell near the micropylar become the egg apparatus, with an egg cell in the center and two synergids. at the other end of the cell, a cell wall forms around the nuclei and forms the antipodals. therefore, the resulting embryo sac is a seven-celled structure consisting of one central cell, one egg cell, two synergid cells, and three antipodal cells.
megaspore