EMBRYO By N., Sam M.S. - 25 A stage in the development of an animal between cleavage of a fertilised egg and birthor hatching. In humans it is called a foetus after 8 weeks. EMBRYO: "The embryo in the egg hatched to become a fluffy yellow chick." Related Psychology Terms ADOLESCENCE (Theories) Piaget’s Theory of Cognitive Development COLOR CIRCLE PRENATAL DEVELOPMENT ASYNCHRONOUS BROOD COLOR REACTIONS ANIMAL BEHAVIOR CHILD PSYCHOLOGY ORAL CHARACTER COLOR BLINDNESS Cite this page: N., Sam M.S., "EMBRYO," in PsychologyDictionary.org, April 7, 2013, https://psychologydictionary.org/embryo/ (accessed November 27, 2022).