Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Identical twins are two offspring resulting from one zygote that, at an early stage of development, separated into two embryos. They share the same genetic material.
These are twins who developed from separate fertilized eggs. They're like two houses built from different blueprints - similar in some ways because they're both houses, but not identical.
Concordance Rate: This is a term used in genetics which indicates the percentage of cases where both twins express a certain trait if one twin expresses that trait. It's like comparing how often both houses need repairs if one house has a problem.
Clone: A clone is an organism or cell that is genetically identical to another. Like creating another house with the exact same blueprint as the first one.