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micropylar造句
(1) Micropylar collar and operculum are absent in micropylar region. (2) TEM image of a section through the micropylar center was obtained. (3) The haustorium cellularizated from the micropylar end to chalazal end at the later globular stage. (4) Ingrowths at the micropylar end of embryo sac from late stage of 1-nucleate to cellularization enlarge the surface of membrane greatly so as to enhance non-symplastic transportation. (5) The polysaccharides in the cells of micropylar and chalazal end increases with the formation of functional megaspore. (6) Wall ingrowths occurred in central cell at micropylar region near embryo sac wall. (7) There are several nucellar cells in micropylar region that develop into embellum. (8) During meiosis, callose deposit on the micropylar end wall of the megasporocyte, but the cell was not enclosed by callose. (9) One of the nuclei at the micropylar pole becomes dlimited by a small amount of cytoplasm. (10) The endosperm development follows the nuclear type. The endosperm cells form at the micropylar end, and remain free nuclear phase at chalazal end. (11) These results suggest that the shape and the size of the micropylar apparatus is favourable for the sperm to penetrate the egg envelop and to block polyspermy. (12) Synergid cells Two haploid cells located near the egg cell at the micropylar end of the embryo sac in flowering plants. (13) Micropylar collar, operculum and parenchyma cells are differentiated at micropylar region. (14) When the free nuclei of the endosperm were 16 or 32, the nucellar embryo initial (s) originated from the nucellar cells near the micropylar end of the embryo sac. (15) The two polar nuclei move from antipodal end to micropylar end before sperm releasing in a gap between egg cell and central cell and subsequently taking off cytoplasm one after another. (16) The free cell wall formation occurs first in the micropylar end when the embryo is 4—6 celled stage, then to the chalazal end and the center.