Developmental biology is the study of the process by which animals and plants grow and develop, and is synonymous with
ontogeny. In animals most development occurs in embryonic life, but it is also found in
regeneration,
asexual reproduction and
metamorphosis, and in the growth and differentiation of
stem cells in the adult organism. In plants, development occurs in embryos, during vegetative reproduction, and in the normal outgrowth of roots, shoots and flowers. Practical outcomes from the study of animal developmental biology have included
in vitro fertilization, now widely used in fertility treatment, the understanding of risks from substances that can damage the fetus (
teratogens), and the creation of various animal models for human disease which are useful in research. Developmental Biology has also help to generate modern stem cell biology which promises a number of important practical benefits for human health.