2 résultats pour "embryology"
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Embryology - biology.
stage a portion of the minute yolk sac is enclosed in the body of the embryo to form a part of the embryonic alimentary canal. At the beginning of its fourth week theembryo, now about 4 to 5 mm (about 0.16 to 0.2 in) long, has the rudiments of eyes and ears, and each side of the neck shows four gill clefts. A tail is also present. Early in the second month the buds of the arms and legs appear. The major internal organs begin to take shape, and in about the sixth week bones and muscles beginto fo...
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Zoology - biology.
is still in its infancy and is quite controversial, chiefly because it has raised anew the old dispute about whether behavior is genetically determined. See Animal Behavior; Sociobiology. Embryology, the study of the development of individual animals, has investigated the way in which developing parts interact—for example, the interactions between theeyestalk and the epidermis during development of the lens of the eye. The emerging field of molecular development applies the techniques of molecu...