blastoderm

American  

[blas-tuh-durm] / ˈblæs təˌdɜrm /

noun

Embryology.

1. the primitive layer of cells that results from the segmentation of the ovum.

2. the layer of cells forming the wall of the blastula, and in most vertebrates enclosing a cavity or a yolk mass.

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blastoderm British  

/ ˈblæstəʊˌdɜːm /

noun

1. the layer of cells that surrounds the blastocoel of a blastula

2. a flat disc of cells formed after cleavage in a heavily yolked egg, such as a bird's egg

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Other Word Forms

• blastodermatic adjective
• blastodermic adjective

Etymology

Origin of blastoderm

First recorded in 1855–60; blasto- + -derm

Example Sentences

Such words as "blastoderm", "sindoc," "peris," "parasang," "sarcenet," "teazel," "nullah," "cantatrice," "barracan," "sistrum," writhed and hissed in her verses.

From Time Magazine Archive

Ectoderm: the outer layer of skin: the outer layer of the blastoderm, giving rise to the nervous system and to epithelial structures of the body surface.

From Explanation of Terms Used in Entomology by Smith, John. B.

The section below is a small portion of the blastodermic area. b.d., blastoderm. y., the undivided yolk. s.c., the segmentation between the blastoderm and yolk.

From Text Book of Biology, Part 1: Vertebrata by Wells, H. G. (Herbert George)

This layer is the blastoderm, the simple epithelium from the cells of which all the tissues of the body proceed.

From The Evolution of Man — Volume 2 by Haeckel, Ernst Heinrich Philipp August

In some parasitic Hymenoptera there is only a single embryonic membrane formed by delamination from the blastoderm, while in a few insects, including the wingless spring-tails, the embryonic membranes are vestigial or entirely wanting.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 4 "Hero" to "Hindu Chronology" by Various