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Location of ovules inside a Helleborus foetidus flower. In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the integument, forming its outer layer, the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center.
Micropyle may refer to: Micropyle (botany) a minute opening in the integument of an ovule of a seed plant. Micropyle (zoology) , a differentiated area of surface in an egg, through which a sperm enters
Placental areas occur in various positions, corresponding to various parts of the carpels that make up the ovary. See Ovule#Location within the plant. An obturator is present in the ovary of some plants, near the micropyle of each ovule. It is an outgrowth of the placenta, important in nourishing and guiding pollen tubes to the micropyle. [17]
(of an ovule) Bent so that both ends are near each other. Contrast anatropous, campylotropous, and orthotropous. amplexicaul With the base dilated and clasping the stem, usually of leaves. amylum star a vegetative propagative body filled with starch (amylum) and located around the lower nodes of certain stonewort s. anastomose
The micropyle, a small pore or opening in the apex of the integument of the ovule where the pollen tube usually enters during the process of fertilization. The chalaza, the base of the ovule opposite the micropyle, where integument and nucellus are joined. [8] The shape of the ovules as they develop often affects the final shape of the seeds.
An ovary with free central placentation, on the other hand, consists of a single compartment without septae and the ovules are attached to a central column that arises directly from the floral apex (axis). In some cases a single ovule is attached to the bottom or top of the locule (basal or apical placentation, respectively).
A micropyle is a pore in the membrane covering the ovum, through which a sperm enters.Micropyles are also found in sporozoites of some digenetic microorganisms such as Plasmodium at the anterior part of the cell that ultimately leads towards the apical cap.
In plant ovules, the chalaza is located opposite the micropyle opening of the integuments. It is the tissue where the integuments and nucellus are joined. Nutrients from the plant travel through vascular tissue in the funiculus and outer integument through the chalaza into the nucellus.