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.
Since organisms have two alleles for each trait, when the alleles of a pair are heterozygous, the dominant allele trait is expressed and the recessive allele trait is masked. Seeds with the genetic makeup of (YY) or (Yy) are yellow, while seeds that are (yy) are green.More Genetics Information: 1  Chromosomes and Sex.ince organisms have two alleles for each trait, when the alleles of a pair are heterozygous, the dominant allele trait is expressed and the recessive allele trait is masked. Seeds with the genetic makeup of (YY) or (Yy) are yellow, while seeds that are (yy) are green. More Genetics Information: 1  Chromosomes and Sex.