Development is the branch of biology with describing and understanding how a egg or spore or bud turns an adult organism. More inclusive than , the term also encompasses such processes regeneration of limbs in many animals vegetative propagation as found in higher . In addition, biologists are interested in relationship between the processes of development those of aging.
Sexual reproduction requires single cell stage. If large multicellular has adaptive advantages, then the life must necessarily include a period of from the single cell to the form. The process of development has components: growth (size increase), morphogenetic movement ( shaping of patterns and forms), and (the change from undifferentiated to specialized ).