Fraternal (Dizygotic) Twins

Definition

Fraternal twins are siblings who develop from separate fertilized eggs. They share half their genes just like any other siblings but they share womb environment at the same time.

Related terms

Monozygotic Twins: Also known as identical twins, these siblings come from one zygote that splits into two embryos; sharing 100% of their genetic material.

Concordance Rate: This refers to how often both twins exhibit certain traits or disorders if one twin has it. It's used to study how much genetics play a role versus environmental factors.

Heritability:

This term refers to how much variation in a trait within a population can be attributed to genetic differences.