In the course of prenatal development, by the end of the period, the heart begins to beat, the arms and legs become more differentiated, the face starts to form, and the intestinal tract appears in human beings.

Embryonic period

Explanation: During the Embryonic period, the three germ layers form the tissues and main organ systems. Infact the body becomes recognizably human.

It is between weeks 3-8 of development.

It is during this period of development that the conceptus is most likely to develop a major congenital malformation.

abraham lincoln issued the preliminary emancipation proclamation on september 22nd, 1862. it stipulated that if the southern states did not cease their rebellion by january 1st, 1863, then proclamation would go into effect.