(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:
Micropyle
Definition:
(n.) An opening in the membranes surrounding the ovum, by which nutrition is assisted and the entrance of the spermatozoa permitted.
(n.) An opening in the outer coat of a seed, through which the fecundating pollen enters the ovule.
Example Sentences:
(1) The micropyle canal measures 8 microns at the opening and tapers to 3.6 microns as it penetrates the membrane.
(2) This stain permits pollen tubes to be traced even up to their entry into the micropyle.
(3) The outer layer formed densely accumulated protrusions, whilst the inner layer was smooth and formed a collar structure around the micropyle.
(4) A micropyle and oocyst residuum are absent, but a polar granule is present.
(5) Only unsporulated oocysts were detected in the intestine, and sporulation occurred when feces containing oocysts were incubated for 48 h in seawater at 21 degrees C. Oocysts are elongated (24.8 x 14.7 micron) with a wall about 200 nm thick and have no residuum, micropyle, or polar granule.
(6) Contrary to the widely accepted view that chiton sperm lack acrosomes and that fertilization in this group occurs via a micropyle, we demonstrate here that fertilization in Tonicella lineata occurs by acrosome-mediated sperm-egg fusion.
(7) Sperm from the white sturgeon, Acipenser transmontanus possess an acrosome while the eggs possess numerous micropyles.
(8) were ovoid, 17.6 X 13.6 (16-20 X 11-16) micron; micropyle and oocyst residuum were absent, but a polar body was present.
(9) The plastron region partially encircles the micropyle (anterior end) of the egg and extends along the dorsal surface to the posterior pole; it is delineated laterally by the hatch lines.
(10) Sperm stored in the spermatheca probably is pumped onto the micropyle of the egg during this pause.
(11) are ellipsoidal, 27.3 x 23.6 (22-30 x 20-27) microns; a polar body is present, but no oocyst residuum or micropyle occurs.
(12) The structure of oocysts is described; a peculiar bumpy surface and a calyx-like thickening around the micropyle are illustrated by scanning electron microscopy.
(13) The oocyst wall is smooth, single-layered, with no micropyle.
(14) This indicates a new function for these cells though previously to contribute mainly in the formation of the micropyle.
(15) Neither micropyle, polar granules, nor oocyst residuum were present.
(16) A rapid and steady growth of pollen tubes, their accumulation near the micropyle and penetration in it are observed in self-fertile plants.
(17) After microinjection into fertilized, nonactivated Atlantic salmon eggs via the micropyle, transgenic Atlantic salmon were generated.
(18) are spheroid or subspheroid, 24.6 x 23.5 (21-27 x 20-25) microns, with a shape index of 1.05 (1.0-1.09) but with no micropyle, oocyst residuum, or polar granules.
(19) A micropyle and micropylar cap were observed, but a polar granule and oocyst residuum were absent.
(20) The oocyst wall is a single, colorless layer about 0.6-1.0 microns thick with no striations or micropyle.