chalaza

American  

[kuh-ley-zuh] / kəˈleɪ zə /

noun

plural

chalazas, chalazae

1. Zoology. one of the two albuminous twisted cords which fasten an egg yolk to the shell membrane.

2. Botany. the point of an ovule or seed where the integuments are united to the nucellus.

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chalaza British  

/ kəˈleɪzə /

noun

1. one of a pair of spiral threads of albumen holding the yolk of a bird's egg in position

2. the basal part of a plant ovule, where the integuments and nucellus are joined

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chalaza Scientific  

/ kə-lā′zə /

plural

chalazae

1. 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. The region of a plant ovule that is opposite the micropyle, where the integuments and nucellus are joined.

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Other Word Forms

• chalazal adjective
• chalazian adjective

Etymology

Origin of chalaza

1695–1705; < New Latin < Greek: hail, lump

Example Sentences

The shape and color of seed offer distinguishing marks, while the size, shape and position of the raphe and chalaza furnish very certain marks of distinction in some species.

From Manual of American Grape-Growing by Hedrick, U. P.

The same, cut through lengthwise: a, the hilum; c, chalaza; d, outer seed coat; e, inner seed-coat; f, the albumen; g, the minute embryo.

From The Elements of Botany For Beginners and For Schools by Gray, Asa

I have been thinking that the apparent opening at the chalaza end must have been withering or perhaps gnawing by some very minute insects, as the ovarium is open at the upper end.

From More Letters of Charles Darwin — Volume 2 by Darwin, Francis, Sir

The adnate portion of the funiculus, which appears as a ridge or cord extending from the hilum to the chalaza, and which distinguishes this kind of ovule, is called the Rhaphe.

From The Elements of Botany For Beginners and For Schools by Gray, Asa

The hilum or base of the seed, and the chalaza or base of the nucellus are united by means of the raphe r.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 "Frost" to "Fyzabad" by Various