A common birth defect characterized by an opening between the upper lip and the nose is called Cleft Lip. Cleft lip happens during the early stage of pregnancy. This occurs when there is an unsuccessful connection in the face and lip area while the fetus is developing inside the womb. Both cleft lip and cleft palate are successfully treated with surgery.
The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cellsarise from existing cells. Rudolf Virchow later made important contributions to this theory. ... Thecell is the fundamental unit of structure and function in living things.