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.