chalaza


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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 ?
The seeds, to 3.5 mm, from anatropous ovules, have a chalaza at the broad end of the seed and hilum at the narrow end.
The seed is orthotropous because the hilum, the chalaza, and the
The chalaza is the region of the ovule where the nucellus, integuments, and funicle merge, and therefore usually encompasses a vascular bundle.
The structure of the proximal end of the nucellus, adjacent to the chalaza, is variable and often includes modifications such as a hypostase or enlarged dermal cells.
The commonest condition for Lilianae (Rudall, 1994) is one where the proximal nucellus is short and broad, without enlarged dermal cells, but often with a hypostase and a fairly extensive subdermal region at the proximal ends around the sides of the embryo sac, but not towards the chalaza. This type occurs in many monocot taxa (e.g., Figs.
Coloracion de capsula cefalica similar a instar dos; epicraneo con cuernos muy pronunciados casi redondos; con chalazas dispuestas de igual forma que instar anterior; mantiene concavidades y granulos.
Capsula cefalica color cafe oscuro, mas claro detras de los cuernos y parte inferior del frontoclipeo; prominentes cuernos casi redondos en vertice y protuberancias tuberculadas (chalazas); mantiene disposicion de chalazas, concavidades y granulos.
Capsula cefalica color cafe oscuro a negro, con una delgada banda mas clara detras de los cuernos; mantiene chalazas, granulos y concavidades; epicraneo con cuernos redondos muy pronunciados.
Cuerpo cafe con linea dorsal y lateral color cafe; cada segmento de la larva posee un par de largas setas primarias dorsales y laterales color blanco que salen de protuberancias amarillas (chalazas), y abundantes setas secundarias mas cortas del mismo color; zona toracica negra con largas setas blancas curvadas hacia delante, que salen de las protuberancias amarillas.
Instar 4: La cabeza y cuerpo similar a instar 3, pero la tonalidad del cuerpo se oscurece; se mantiene y oscurece la linea dorsal central y las setas blancas largas sobre las protuberancias (chalazas) amarillas; la superficie se observa densamente cubierta de otras pequenas protuberancias amarillas de donde salen las setas secundarias mas cortas.
Instar 5: Capsula cefalica y cuerpo similar a instar 4; el tono del cuerpo se oscurece aun mas; se observa menos densa la superficie de setas secundarias, se mantienen las chalazas amarillas con las largas setas blancas (Figura 8).