Concordance as used in genetics means the presence of the same trait in both members of a pair of twins, or in sets of individuals. Jump to: navigation, search Genetics (from the Greek genno γεννώ= give birth) is the science of genes, heredity, and the variation of organisms. ... In biology, a trait or character is a genetically inherited feature of an organism. ... Fraternal twin boys in the tub The term twin most notably refers to two individuals (or one of two individuals) who have shared the same uterus (womb) and usually, but not necessarily, born on the same day. ...

A twin study examines the concordance rates of twins having the same trait, especially a disease, which can help determine how much the disease is affected by genetics versus environment. Jump to: navigation, search A twin study is a kind of genetic study done to determine heritability. ...

Because identical twins have identical DNA, it follows that they would be affected by the same genetic diseases. This is usually true for monogenic diseases, but is not always true of polygenic diseases. Jump to: navigation, search Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and most viruses). ...

Controversial uses of twin data have looked at concordance for homosexuality and intelligence. Jump to: navigation, search Since its coining, the term homosexuality has acquired multiple meanings. ... Intelligence is usually said to involve mental capabilities such as the ability to reason, plan, solve problems, think abstractly, comprehend ideas and language, and learn. ...