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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.
[1] The identity of the organs present in the four floral verticils is a consequence of the interaction of at least three types of gene products, each with distinct functions. According to the ABC model, functions A and C are required in order to determine the identity of the verticils of the perianth and the reproductive verticils ...
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.
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 ...
Retinoic acid, an important signaling molecule needed throughout embryogenesis, acts through the Hox genes. It was originally postulated that retinoic acid acts to induce the Hoxb-8 gene, [ 11 ] but this hypothesis has not been supported by genetic studies in mouse embryos lacking retinoic acid synthesis that still express Hoxb-8 in the limb. [ 8 ]
During embryogenesis, for a number of cell cleavages (the specific number depends on the type of organism) all the cells of an embryo will be morphologically and developmentally equivalent. This means, each cell has the same development potential and all cells are essentially interchangeable, thus establishing an equivalence group .
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 ...