The origin and development of organs in animals and plants.

The germ history of the organs and systems of organs, -- a branch of morphogeny.

Development of individual plant organs such as leaves, tillers, floral organs, or roots.

The formation of organs during development.

The time period during embryonic development in which all major organs and organ systems are formed. During this period, the embryo is most susceptible to factors interfering with development.

or-GAN-o-gen-eh-sis Development of organs in an embryo. 226

A term used in embryology to describe the period between two weeks and eight weeks of gestation when the baby experiences rapid growth in organ and organ systems development. During this period the baby is extremely vulnerable to environmental hazards and toxic substances and any interference with the sequential processes may result in congenital abnormalities.

An early period of rapid embryonic development in which the organs take form from the primary germ layers.

Gr. organon - organ; Gr. genesis - origin, descent]. Formation of organs in the developing embryo.

In animal development, organogenesis is the process by which the ectoderm, endoderm, and mesoderm develop into the internal organs of the organism. The germ layers in organogenesis differ by three processes: folds, splits, and condensation. Developing early during this stage in chordate animals are the neural tube and notochord.