Chalaza

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Related to chalazal: Chalazal spot

chalaza

[kə′lāz·ə]
(botany)
The region at the base of the nucellus of an ovule; gives rise to the integuments.
(cell and molecular biology)
One of the paired, spiral, albuminous bands in a bird's egg that attach the yolk to the shell lining membrane at the ends of the egg.

Chalaza

 

the basal part of the ovule where the seed stalk attaches the ovule to the placenta.

References in periodicals archive ?
3H), whereas the three antipodal cells at the chalazal end were ephemeral and degenerated soon after fertilization.
Near the end of free nuclear development of the functional female gametophyte, a small and distinctive chalazal region differentiates [ILLUSTRATION FOR FIGURES 3F-H OMITTED].
Usually near the chalazal megaspore developed into the functional megaspore while the other three megaspores were eventually degenerated (Fig.
Only one megaspore functions and it is always one of the two larger chalazal members of the tetrad (Fig.
the number of cell layers in the chalazal region and the free
intybus, the chalazal megaspore of the linear- shaped tetrad gives rise to form Polygonum type of embryo sacasdescribedformorethan70%ofangiosperm (Maheshwari, 1950; Batygina, 1987).
Fruit mostly a pair of ventrally dehiscent follicles (often only one due to abortion) (rarely a capsule), with small seeds with a micropylar coma, rarely with a chalazal coma or ecomose (fruits in Rauvolfioideae drupes, berries, follicles, or capsules; seeds usually ecomose, naked, winged, or arillate).
During the early apomeiotic prophase, vacuoles accumulate in the chalazal region of the MMC, the nucleus moves to the center of the MMC, and callose, which normally envelops sexual MMCs during meiosis (Rodkiewicz, 1970), is generally absent (restricted to the wall of the MMC closest to the micropyle when present).
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.