Embryogenesis - Research Article from Macmillan Science Library: Plant Sciences

This encyclopedia article consists of approximately 3 pages of information about Embryogenesis.
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Dicot and Monocot Embryos

The first division of the zygote is almost always asymmetric (uneven) and transverse to its long axis, producing a small apical cell and a large basal (bottom) cell. The apical cell then divides, forming a longitudinal wall, and then divides again, forming a second wall at right angles to the first, to generate a four-celled embryo; subsequent divisions give rise to a globular embryo of eight to thirty-two cells. By changes in shape, accompanied by tissue and organ formation, the globular embryo successively forms the heart-shaped, torpedo-shaped, walking-stick-shaped, and mature embryo.

In contrast, the basal cell divides by a series of transverse walls to form a filamentous structure known as the suspensor, which anchors the embryo to the embryo sac wall and aids in nutrient absorption from the surrounding tissues. Typically in dicots, the mature embryo consists of the shoot apex, the two cotyledons (seed...

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This section contains 863 words
(approx. 3 pages at 300 words per page)
Buy the Embryogenesis Encyclopedia Article
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Macmillan Science Library: Plant Sciences
Embryogenesis from Macmillan Science Library: Plant Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
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