noun, Pathology. 1. the accumulation of excessive ketones in the body, as in diabetic acidosis. Origin of ketosis. 1915-1920.
Climate zones of Africa, showing the ecological break between the hot desert climate of the Sahara Desert (red), the hot semi-arid climate of the Sahel (orange) and the tropical climate of Central and Western Africa (blue).
North Africa, consisting of the Sahara and north, in the northern red climatic zone and northwards. Sheltered valleys in the Atlas Mountains, the Nile Valley and delta, and the Mediterranean coast are the main sources of fertile farming land.