A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Facts about Identical Twins

Identical (monozygotic) twins are always of the same sex because they form from a single zygote (fertilized egg) that contains either male (XY) or female (XX) sex chromosomes. ... A set of boy/girl twins can only be fraternal (dizygotic). Boy/girl twins cannot be identical (monozygotic).Oct 23, 2017

Related Types