The theoretical model builds on the concept of continental drift developed during the first few decades of the 20th century. The geoscientific community accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s. The lithosphere, which is the rigid outermost shell of a planet (the crust and upper mantle), is broken up into tectonic plates.
These disorders are known as monogenetic disorders (disorders of a single gene). Some examples of monogenetic disorders include: 1  cystic fibrosis, 2  sickle cell anemia,3  Marfan syndrome, 4  Huntington's disease, and.5  hemochromatosis.ome examples of monogenetic disorders include: 1  cystic fibrosis, 2  sickle cell anemia, 3  Marfan syndrome, 4  Huntington's disease, and. 5  hemochromatosis.
Genetic disorders can be grouped into three different categories. Single gene disorders result from a change or mutation in a single cell. Cystic fibrosis is an example of this type of disorder. Chromosome disorders are caused by too few or too many genes located on chromosomes, or other changes in chromosomes.