(n.) The place on an ovule, or seed, where its outer coats cohere with each other and the nucleus.
(n.) A spiral band of thickened albuminous substance which exists in the white of the bird's egg, and serves to maintain the yolk in its position; the treadle.
Example Sentences:
Nucellus
Definition:
(n.) See Nucleus, 3 (a).
Example Sentences:
(1) The dynamics of growth processes was studied in the integument and nucellus of Pinus silvestris during the year of fertilization.
(2) The growth of micropylar part of the nucellus and integument proceeds, mainly at the expense of cell proliferation.
(3) Pollination stimulated accumulation of several reserve substances and enzymes in the tip of nucellus beak, micropylar zone and these included starch, peroxidase, phosphorylase succinate dehydrogenase, cytochrome oxidase etc.
(4) Nucellus cells also stored diverse substances and enzymes especially towards the chalazal end.
(5) Recovery from the repressor did not occur readily in Citrus nucellus following recultures in citron-ovule-free medium; carrot callus resumed normal embryogenesis immediately upon transfer to suppressor-free medium.
(6) The larges nuclei are situated in the micropylar part of nucellus.
(7) Citrus reticulata Blanco Ponkan mandarin nucellus explants and Daucus carota L. 'Queen Anne's Lace' callus were employed to examine effects of known plant growth regulators and to determine possible identity of one or more of them with the repressive factor.
(8) In the part of nucellus concrescent with the integument, the mitotic activity disappears still prior to fertilization and the growth proceeds, mainly, at the expense of cell elongation.
(9) It could arise from a damage of the feeding function of the nucellus.
(10) The nucellus of Zea mays contains many enzymes required for hydrolysis of reserved food substances.
(11) The growth of two parts of the nucellus and integument under study is described by an S-shaped curve but the dynamics of growth processes and the ratio of cell reproduction and elongation differ in each tissue.
(12) In ovaries sampled before and after fertilization, a 3H-labeled histone RNA probe was localized in the cells of the pericarp, outer integument and nucellus but binding of the probe decreased as these tissues senesced.
(13) Pollination stimulated the accumulation of several substances and enzymes in the tip of the nucellus, micropylar zone.