Search results
Results from the WOW.Com Content Network
Plant embryonic development, also plant embryogenesis, is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination . [ 1 ]
[1] [3] In the frog Xenopus laevis, the animal pole is heavily pigmented while the vegetal pole remains unpigmented. [4] A pigment pattern provides the oocyte with features of a radially symmetrical body with a distinct polarity. The animal hemisphere is dark brown, and the vegetal hemisphere is only weakly pigmented.
Polar auxin transport (PAT) is directional and active flow of auxin molecules through the plant tissues. The flow of auxin molecules through the neighboring cells is driven by carriers (type of membrane transport protein) in the cell-to-cell fashion (from one cell to other cell and then to the next one) and the direction of the flow is determined by the localization of the carriers on the ...
In seed plants, the embryo will develop one or more "seed leaves" . By the end of embryogenesis, the young plant will have all the parts necessary to begin its life. Once the embryo germinates from its seed or parent plant, it begins to produce additional organs (leaves, stems, and roots) through the process of organogenesis.
Somatic embryogenesis is an artificial process in which a plant or embryo is derived from a single somatic cell. [1] Somatic embryos are formed from plant cells that are not normally involved in the development of embryos, i.e. ordinary plant tissue. No endosperm or seed coat is formed around a somatic embryo.
The second mechanism of unequal cleavage involves the production of an enucleate, membrane bound, cytoplasmic protrusion, called a polar lobe. [8] This polar lobe forms at the vegetal pole during cleavage, and then gets shunted to the D blastomere. [7] [8] The polar lobe contains vegetal cytoplasm, which becomes inherited by the future D ...
One sperm fertilizes the egg cell and the other sperm fuses with the two polar nuclei of the large central cell of the megagametophyte. The haploid sperm and haploid egg fuse to form a diploid zygote, the process being called syngamy , while the other sperm and the diploid central cell fuse to form a triploid primary endosperm cell (triple fusion).
This distinction of layers of the bilaminar disc defines the primitive dorso ventral axis and polarity in embryogenesis. [2] The epiblast migrates away from the trophoblast downwards, forming the amniotic cavity in between, the lining of which is formed from amnioblasts developed from the epiblast. The hypoblast is pushed down and forms the ...