chalaza

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Related to chalazal: Chalazal spot

cha·la·za

(kă-lā'ză),
1. Synonym(s): chalazion
2. Suspensory ligament of the yolk in a bird's egg.
[G. hail; a small tubercle, a sty (Galen)]

chalaza

(kə-lā′zə, -lăz′ə)
n. pl. chala·zae (-zē) or chala·zas
1. Biology One of two spiral bands of tissue in an egg that connect the yolk to the lining membrane at either end of the shell.
2. Botany The region of an ovule that is opposite the micropyle, where the integuments and nucellus are joined.

cha·la′zal adj.

chalaza

  1. the basal part of the OVULE of a flowering plant to which the FUNICLE is attached, and through which the pollen tube sometimes enters the ovule prior to fertilization.
  2. one of an opposite pair of spiral bands in the white of a bird's egg which suspend the yolk within the shell to prevent it from being damaged.
References in periodicals archive ?
Immediately after fertilization, the densely cytoplasmic chalazal region of the female gametophyte is partitioned by cell walls [ILLUSTRATION FOR FIGURES 5A-F OMITTED].
Approximately three days after fertilization, nuclei within each multinucleate cell of the chalazal region fuse.
Three antipodal cells were located at the chalazal pole and generally degenerated soon (Fig.
The antipodals, formed from the three nucleus of chalazal quartet, are situated on the periphery at the chalazal end of the ES (Fig.
The author described the occurence of ten types of tetrads (linear with chalazal or epichalazal functional megaspore, T-shaped, oblique linear, inverted T- shape, anisobilateral, triad and three different types of bisporic patterns) and supposed evolutionary lines with in the family.
In Polygonum type development of embryo sac, antipodal cells are placed on the chalazal end of embryo sac.
The following anomalies were infrequently observed among [B.sub.III] florets: (i) pairs of MMCs developing parallel to each other (eight pistils), (ii) functionality of the micropylar rather than the chalazal cell of dyads (five pistils), and (iii) adventitious pistil formation from anther surfaces (about 30-40% of the florets from one [B.sub.III] somaclone).
Fruit usually a pair of slender to stout, thinly to thickly woody, ventrally dehiscent follicles with dry pericarp; endocarp not forming a stone; seeds usually numerous, compressed, with coma usually on micropylar end, sometimes with a coma at the chalazal end or at both micropylar and chalazal ends (some Wrightieae and Malouetieae), rarely ecomose (s ome Malouetieae); endosperm thin, not ruminate.
Other nucellar and chalazal structures, such as hypostase, perisperm, and chalazosperm, are regarded as being of some systematic significance in monocotyledons and are used as characters in analyses.
Dyads and triads, including binucleated functional megaspores, were also identified and resulted from the absence of cytokinesis after telophase II in both chalazal and micropylar cells (Fig.
The active part during the development of rumination may be the endosperm (e.g., Andrographis, Acanthaceae: Mohan Ram, 1960) as well as chalazal or integumentary tissue.