The stages of development of the unborn child are embryo and fetus. An embryo undergoes a series of cell division and development to form a fetus. The embryo is called a fetus at two months. The sex of the child is determined by the father's chromosomes. After birth the stages of life are infancy, childhood, adolescence, adulthood, and older adulthood.
Some human traits are the result of environment rather than heredity.
For example, facial characteristics and mental ability can be different due to a mother consuming large amounts of alcohol during pregnancy. Growth rate is greatest during the first two years of life and during adolescence. The University of Tennessee at Martin is not responsible for the information or views expressed here.