dizygotic
Studies of identical and non-identical twins suggest that co-operative behaviour is heritable.
Identical twins, who have the same genes, were more likely to have a similar number of moles and freckles than non-identical twins.
Ellen gave birth to two non-identical twin boys, Brian and Roger.

SMART Vocabulary: related words and phrases

Parents & children
baby mama
babyhood
babymoon
bastard
brat
fraternal twin
guardianship
identical twin
illegitimacy
parent
parentage
parental
parentally
parenthood
step-parent
the generation gap
triplet
tug of love
twin
without issueidiom