Word Origin and History for mesopotamian. ancient name for the land that lies between the Tigris and Euphrates rivers (in modern Iraq), from Greek mesopotamia (khora), literally a country between two rivers, from fem. of mesopotamos, from mesos middle (see medial (adj.)) + potamos river (see potamo-).
Monogenic forms, caused by a single mutation in a dominantly or recessively inherited gene, are well-established, albeit relatively rare types of PD. They collectively account for about 30% of the familial and 3%â5% of the sporadic cases.
There are three combinations of genotypes or alleles: AA (receives dominant traits from both parents), Aa (receives a dominant trait from one parent and a recessive trait from the other), and aa (receives recessive traits from both parents). Eye color is one example wherein dominant genes mask recessive genes..A dominant gene is one which is strong while a recessive gene is one which is weak. 3.A dominant gene will show up in the trait while a recessive gene, although still present, is masked or hidden by the dominant gene.