0 Monozygotic twins (= two babies born to the same mother at the same time) develop from just one egg. -- 同卵的（指雙胞胎從單卵分裂發育而成，即同卵雙胞胎）
A consistent finding from these studies is the lack of complete concordance among monozygotic twins for many disorders that are known to be inherited.
Learning and memory in monozygotic twins discordant for schizophrenia.
Concordance rates differed significantly across monozygotic and dizygotic twin pairs for broadly defined self-reported anorexia nervosa and bulimia nervosa.
A controlled study of brain structure in monozygotic twins concordant for schizophrenia.
The importance of environmental influences is further supported by the observation of phenotypic differences in the lesions of monozygotic twins.
These studies compare the occurrence of an illness in monozygotic and dizygotic sets of twins.
The marked progression in the dependence of monozygotic, dizygotic and trizygotic rates on maternal age underlines the importance of this factor in multiple birth studies.
If both members of a pair responded "almost always," "always," or "often," they were classified as monozygotic.
