micropyle


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Related to micropyle: embryo sac, synergid, antipodal cells

mi·cro·pyle

(mī'krō-pīl),
1. Minute opening believed to exist in the investing membrane of certain oocytes as a point of entrance for the sperm.
2. Former name for micropore.
[micro- + G. pylē, gate]

micropyle

(mī′krə-pīl′)
n.
Zoology A pore in the membrane covering the ovum of some animals through which a spermatozoon can enter.

mi′cro·py′lar adj.

micropyle

a small canal in the integument surrounding the ovule of a flowering plant, through which the POLLEN TUBE usually enters the ovule on the way to the EMBRYO SAC. Water enters the seed via the micropyle prior to GERMINATION.

micropyle

an opening through which a spermatozoon enters certain ova.
References in periodicals archive ?
1991, "Introduction to fish spermatozoa and the micropyle," In: Fish evolution and systematic.
Microbes could bypass the tedious process of decomposing the seed coat if they could gain access directly via pre-designed weak spots, such as hilum, strophiole, chalaza, or micropyle, or via entrances created by cracks, nicks or wrinkles in the seed coat.
The obpyramidal seeds are attached to a central placenta in rows, have a thick testa with rounded comers, a sub-basal micropyle, spongy parenchyma within, and are 2-3 x 1.
The site of direct pollen reception itself in most gymno-ovulate plants is the pollination drop, a drop of fluid (mainly water) secreted through the micropyle of the ovule.
Single polar granule occasionally present, attached either to oocyst residuum or sporocyst; micropyle absent.
Winged fruits have many characters potentially useful for identification including size, number of wings, patterns of wing venation, wing shape and position, persistence of style(s) and pedicel, placentation type, seed number and orientation, position of micropyle and raphe, and epidermal anatomy.
A micropyle was reported to be present for a few of the oocysts, which we interpret here to represent the small bump observed on about 10 percent of the outer wall surfaces.
secretes a small droplet of mucilaginous fluid from its micropyle, which
sections of the regions of the micropyle and of the hilum.
The Cacteae dade is supported (b86/j83% and b70/ j67%) by various structural features, but only one of them, the occurrence of a disjunct hilum and micropyle in their seeds (63), is a synapomorphy.
High temperatures induced germination of Rhus ovata seeds by rupturing the second seed-coat layer along the edge of the seed first above the micropyle.