Development of the embryo sac of a flower, animation. The embryo sac is the structure that produces the female gametes (sex cells). It develops within the flower's ovule. A megaspore mother cells undergoes meiosis to produce four haploid megaspore cells, three of which then degenerate. The remaining megaspore undergoes three mitotic divisions to produce eight nuclei. One of these becomes the ovum (egg cell), two become synergids, two become polar nuclei and three become antipodal nuclei. Upon fertilisation two sperm cells from the male gamete are released into the ovule. One fuses with the ovum to form a diploid zygote, which becomes the seed, the other fuses with both polar bodies to form a triploid primary endosperm. | |
Licence : | Droits gérés |
Crédit : | Science Photo Library / Biocosmos / Francis Leroy & Michael Pierard |
Model Release : | Non requis |
Durée : | 45 Secondes |
Aspect ratio : | 16/9 |
Restrictions : | - |